Fix typos discovered by codespell

[cclauss]

Fix typos discovered by codespell - https://pypi.org/project/codespell

% codespell

./create_protobuf.py:24: protcol ==> protocol
./docs/usage/protocol.rst:15: recieve ==> receive
./src/sass_embedded/simple.py:143: srouce ==> source
./src/sass_embedded/simple.py:145: addtional ==> additional
./src/sass_embedded/simple.py:184: addtional ==> additional
./src/sass_embedded/simple.py:230: addtional ==> additional
./src/sass_embedded/protocol/compiler.py:102: Recieve ==> Receive

% codespell --write-changes

[attakei]

Thanks!!!