Revert "Add a "Tools & Frameworks" section"

This reverts commit 0a811a13b8b73b7eccab07debd1670fff3a9d1d0.
Revert "Update list of systems that inspired our practices"

This reverts commit 8eaaf375d3321ef533117df97934ea020a9dcde7.
Revert "Style opening text to appear more like pretext"

This reverts commit ca683e4d23a0b054c17f49b122d6e8378d5311e0.
Revert "Fix merge conflicts"

This reverts commit b529091af5ac3f3cd41b4e1a19142264db0f14a2.
Revert "Add missing links"

This reverts commit cef2986470705684497b5d563d59eaf416db1c71.