[Keymap] Crkbd/keymaps/oo (#12882)

keyboards/crkbd/keymaps/oo/readme.md

@@ -0,0 +1,19 @@
+# Build instructions
+
+```zsh
+# if this is a fresh install of QMK, don't forget to run setup
+# or you might be missing necessary tools and libraries!
+# https://docs.qmk.fm/#/newbs_getting_started
+$ qmk setup
+
+# using json via the configurator can be easier than starting from scratch
+# but you will need to go back and make the formatting readable for future edits
+$ qmk json2c -o keymap.c keymap.json
+
+# compile; use appropriate tool for your microcontroller
+$ qmk compile -kb crkbd/rev1/common -km oo
+
+# flash; each side has to be done separately
+$ qmk flash -kb crkbd/rev1/common -km oo
+
+```