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

doc/build-osx.md

@@ -18,6 +18,8 @@ Dependencies
 
     brew install automake berkeley-db4 libtool boost --c++11 miniupnpc openssl pkg-config protobuf python3 qt libevent
 
+See [dependencies.md](dependencies.md) for a complete overview.
+
 If you want to build the disk image with `make deploy` (.dmg / optional), you need RSVG
 
     brew install librsvg