add todo about URL changes

- [ ] Compute language bar graph based on lines of code, not count of files
  - Also make a way for users to ignore certain files or filetypes
- [ ] Amending a commit can make it incorrectly show up as being in one branch but not the other (see e6bbc544eb7000015a)
- [ ] Sorting branch list dropdown by last commit isn't sorting correctly
- [ ] Change URL scheme for snapshotted pages to account for:
  - branch snapshots
  - tag snapshots
  - commit snapshots (i.e. when they are mentioned in a blog post)

### Completed