chore: remove docs/common submodule

Utility libraries don't need the formal documentation templates
designed for hybrid architecture applications. A simple README
and inline documentation suffice.

Author: abitofhelp

.gitmodules

@@ -4,6 +4,3 @@
 [submodule "test/python"]
 	path = test/python
 	url = https://github.com/abitofhelp/hybrid_test_python.git
-[submodule "docs/common"]
-	path = docs/common
-	url = https://github.com/abitofhelp/hybrid_lib_docs.git