Merge pull request #205 from pw374/redesign

some fixes for the redesign branch (usage of OMD in Makefiles and dependencies in README)
remove platform from nav bar
change platform to package on homepage

This makes more sense for the time being, especially
as OPAM is part of the Platform efforts.
Merge pull request #207 from amirmc/platform-page

Changes to how Platform page is linked
fix link to Jane St (closes #191)
fix #200
part fix for #204
partial fix for #204
remove extra leading spaces in code blocks
fix link (packages=>https://opam.ocaml.org/pkg/)
fix link (missing .html)
fix link
Fix "Syntax error: redirection unexpected".
Use recursive make.
Use -linkpkg instead of enumerating the modules.
Ignore files generated by compiling.
Use $(RM) instead of `rm -f`.
note about mpp version
Rename README-redesign.md to README.md
remove unused rule + update clean