fix getFileExtension missing numeric extensions (e.g. mp4)

Jacky Zhao

2023-08-09 e4950e06a15e34134b9feb064749748080bd59a1

 content/features/upcoming features.md

@@ -7,6 +7,7 @@
- block links: https://help.obsidian.md/Linking+notes+and+files/Internal+links#Link+to+a+block+in+a+note
- note/header/block transcludes: https://help.obsidian.md/Linking+notes+and+files/Embedding+files
- static dead link detection
- docker support

## misc