Add showcase entry for October + update homepage carousel entry for October (#1436)

* Add showcase entry for October

* Update home carousel image for October

website/docs/community/showcase/october.mdx

@@ -0,0 +1,11 @@
+# October
+
+<p style={{"text-align": "center"}}>
+   <img src="/img/showcase/october.png"></img><br/>
+</p>
+
+[October](https://october.utf9k.net) is a small Wails application that makes it really easy to extract highlights from [Kobo eReaders](https://en.wikipedia.org/wiki/Kobo_eReader) and then forward them to [Readwise](https://readwise.io).
+
+It has a relatively small scope with all platform versions weighing in under 10MB, and that's without enabling [UPX compression](https://upx.github.io/)!
+
+In contrast, the author's previous attempts with Electron quickly bloated to several hundred megabytes.