Change docs links to actual file extension (.md)

See https://gerrit-review.googlesource.com/83950 for detailed context.

Change-Id: If9d4f0726a0d8d3ca66f01819eeada2b53ac41be
1 file changed
tree: 5e3b73258adc441ed4d39089b462d588bb203356
  1. src/
  2. .gitignore
  3. BUCK
  4. LICENSE