Revert "docs: use collections to structure the data"

This reverts commit 5e8ff010a1.

This broke all the URLs, we can't have that. (And actually, we probably don't
_want_ to make the change either. It's nicer to have all the pages in one
directory, so one doesn't have to figure out to which collection the page
belongs.)

README.md

@@ -26,13 +26,13 @@ Information about build requirements is provided in the [README file](README).
 
 Consult our [NEWS file](NEWS) for information about what's new in the most recent systemd versions.
 
-Please see the [Code Map](docs/_contributing/ARCHITECTURE.md) for information about this repository's layout and content.
+Please see the [Code Map](docs/ARCHITECTURE.md) for information about this repository's layout and content.
 
-Please see the [Hacking guide](docs/_contributing/HACKING.md) for information on how to hack on systemd and test your modifications.
+Please see the [Hacking guide](docs/HACKING.md) for information on how to hack on systemd and test your modifications.
 
-Please see our [Contribution Guidelines](docs/_contributing/CONTRIBUTING.md) for more information about filing GitHub Issues and posting GitHub Pull Requests.
+Please see our [Contribution Guidelines](docs/CONTRIBUTING.md) for more information about filing GitHub Issues and posting GitHub Pull Requests.
 
-When preparing patches for systemd, please follow our [Coding Style Guidelines](docs/_contributing/CODING_STYLE.md).
+When preparing patches for systemd, please follow our [Coding Style Guidelines](docs/CODING_STYLE.md).
 
 If you are looking for support, please contact our [mailing list](https://lists.freedesktop.org/mailman/listinfo/systemd-devel), join our [IRC channel #systemd on libera.chat](https://web.libera.chat/#systemd) or [Matrix channel](https://matrix.to/#/#systemd-project:matrix.org)
 

docs/API_FILE_SYSTEMS.md

@@ -50,4 +50,3 @@ You have three options:
 1. Disable any mounting on `/tmp` so that it resides on the same physical file system as the root directory. For that, execute `systemctl mask tmp.mount`
 2. Mount a different, physical file system to `/tmp`. For that, simply create an entry for it in `/etc/fstab` as you would do for any other file system.
 3. Keep `/tmp` but increase/decrease the size of it. For that, also just create an entry for it in `/etc/fstab` as you would do for any other `tmpfs` file system, and use the right `size=` option.
-

docs/ARCHITECTURE.md

@@ -145,7 +145,7 @@ as a normal executable and executed for each of the input samples under
 with sanitizers and invoked as part of the test suite (if `-Dfuzz-tests=true`
 is configured). Thirdly, fuzzers are executed through fuzzing engines that try
 to find new "interesting" inputs through coverage feedback and massive
-parallelization; see the links for oss-fuzz in [Code quality](CODE_QUALITY).
+parallelization; see the links for oss-fuzz in [Code quality](CODE_QUALITY.md).
 For testing and debugging, fuzzers can be executed as any other program,
 including under `valgrind` or `gdb`.
 

docs/BOOT.md

@@ -109,4 +109,3 @@ Links:
 [https://github.com/systemd/systemd](https://github.com/systemd/systemd)
 
 [http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/](http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/)
-

docs/BOOT_LOADER_INTERFACE.md

@@ -78,7 +78,7 @@ variables. All EFI variables use the vendor UUID
   * `1 << 1` → The boot loader honours `LoaderConfigTimeoutOneShot` when set.
   * `1 << 2` → The boot loader honours `LoaderEntryDefault` when set.
   * `1 << 3` → The boot loader honours `LoaderEntryOneShot` when set.
-  * `1 << 4` → The boot loader supports boot counting as described in [Automatic Boot Assessment](AUTOMATIC_BOOT_ASSESSMENT).
+  * `1 << 4` → The boot loader supports boot counting as described in [Automatic Boot Assessment](AUTOMATIC_BOOT_ASSESSMENT.md).
   * `1 << 5` → The boot loader supports looking for boot menu entries in the Extended Boot Loader Partition.
   * `1 << 6` → The boot loader supports passing a random seed to the OS.
   * `1 << 13` → The boot loader honours `menu-disabled` option when set.

docs/CATALOG.md

@@ -65,4 +65,3 @@ To add message catalog entries for log messages your application generates, plea
 * Use the [native Journal logging APIs](http://0pointer.de/blog/projects/journal-submit.html) to generate your messages, and define message IDs for all messages you want to add catalog entries for. You may use `journalctl --new-id128` to allocate new message IDs.
 * Write a catalog entry file for your messages and ship them in your package and install them to `/usr/lib/systemd/catalog/` (if you package your software with RPM use `%_journalcatalogdir`)
 * Ensure that after installation of your application's RPM/DEB "`journalctl --update-catalog`" is executed, in order to update the binary catalog index. (if you package your software with RPM use the `%journal_catalog_update` macro to achieve that.)
-

docs/CODE_QUALITY.md

@@ -75,7 +75,7 @@ available functionality:
 
 15. Each PR is automatically tested with [Address Sanitizer](https://clang.llvm.org/docs/AddressSanitizer.html)
     and [Undefined Behavior Sanitizer](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html).
-    See [Testing systemd using sanitizers](TESTING_WITH_SANITIZERS)
+    See [Testing systemd using sanitizers](TESTING_WITH_SANITIZERS.md)
     for more information.
 
 16. Fossies provides [source code misspelling reports](https://fossies.org/features.html#codespell).

docs/CONTRIBUTING.md

@@ -29,13 +29,13 @@ For older versions that are still supported by your distribution please use resp
 
 ## Security vulnerability reports
 
-See [reporting of security vulnerabilities](SECURITY).
+See [reporting of security vulnerabilities](SECURITY.md).
 
 ## Posting Pull Requests
 
 * Make sure to post PRs only relative to a recent tip of the `main` branch.
-* Follow our [Coding Style](CODING_STYLE) when contributing code. This is a requirement for all code we merge.
-* Please make sure to test your change before submitting the PR. See the [Hacking guide](HACKING) for details on how to do this.
+* Follow our [Coding Style](CODING_STYLE.md) when contributing code. This is a requirement for all code we merge.
+* Please make sure to test your change before submitting the PR. See the [Hacking guide](HACKING.md) for details on how to do this.
 * Make sure to run the test suite locally, before posting your PR. We use a CI system, meaning we don't even look at your PR if the build and tests don't pass.
 * If you need to update the code in an existing PR, force-push into the same branch, overriding old commits with new versions.
 * After you have pushed a new version, add a comment explaining the latest changes. If you are a member of the systemd project on GitHub, remove the `reviewed/needs-rework`/`ci-fails/needs-rework`/`needs-rebase` labels.

docs/CONVERTING_TO_HOMED.md

@@ -16,10 +16,10 @@ it might be desirable to convert an existing, traditional user account to a
 
 Before continuing, please read up on these basic concepts:
 
-* [Home Directories](HOME_DIRECTORY)
-* [JSON User Records](USER_RECORD)
-* [JSON Group Records](GROUP_RECORD)
-* [User/Group Record Lookup API via Varlink](USER_GROUP_API)
+* [Home Directories](HOME_DIRECTORY.md)
+* [JSON User Records](USER_RECORD.md)
+* [JSON Group Records](GROUP_RECORD.md)
+* [User/Group Record Lookup API via Varlink](USER_GROUP_API.md)
 
 ## Caveat