Found this typo while reading the documentation.
Not sure if this everything that is needed since i'm not familiar with
how docs are generated but hope this helps :)
Please close this PR if i'm missing something
This commit also generally cleans up the Installation docs and uses /includes/<platform>/steps-*.rst as a pattern for storing platform-specific tutorials within a single root URL.
Finally, due to API rate limits, this commit adds some Makefile magic to allow skipping of sync'ing dependencies. Pass `make BUILD_DEPENDENCIES=FALSE <platform>` to skip building any deps and use what is already in the branch.
