Merge #10779: Create dependencies.md
e91b96192 Create dependencies.md, and link dependencies file from README & build docs (flack)
Pull request description:
As @fanquake mentioned in #8639, this should probably be a file in `doc/`, so I went ahead and pulled the issue text via the github API and dumped it into a file. No modifications made, except one spelling fix. This makes the info easier to find, and it will get a proper version history, too.
Tree-SHA512: 6ba4c37c97200972a74724e0e346d6ad5947c01ad18638e15250f2b4cd747dd744aba16e306c98d59f35736542a5eded7a17b6a5ce6aebc63c0a9dc969b365ef