Update TODOs in README for clarity and accuracy (#97)

Signed-off-by: Stanislav (Stanley) Modrak <44023416+smith558@users.noreply.github.com>

Author: smith558

README.md

@@ -20,11 +20,12 @@ The whole thing is completely free to read online, but the original is also avai
 
 ## TODOs:
 - [ ] refactor web code
-- [x] make content mobile-friendly
+- [ ] make UI more modern (whilst retaining as much of the original "feel" as possible)
+- [x] make content pages mobile-friendly (*still needs work)
 - [ ] make homepage mobile-friendly
 - [x] prepare "content edit request" interface on GitHub
 - [ ] add exercises
-- [ ] update (just overall, the outdated parts)
+- [ ] update content (just overall, the outdated parts)
 
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