Fix some typos found while reading various documents, mostly those
relating to the castore.
Here is a summary of the edits.
- fix broken link between documents in the store and castore directories
- clarify expression in castore's data model document that indicates
that the *name* of each child node of a directory must be unique
across all three lists of children
- add missing closing parenthesis in castore's data model document
- replace "how" with "what" in the phrase "unclear how a ... would even
look like" in castore's why-not-git-trees document
- remove unnecessary articles in castore's blobstore chunking document
- add missing "y" to "optionall" in eval's compilation of bindings
document
Change-Id: I1997ea91bb4e9c40abcd81e0cde9405968580ba6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11763
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
