Make the installation documentation not bound to the Python version
Make the installation documentation not bound to the Python version

Also use double grave accent characters (`) to format in a monospace
font.

ari3s/portingdb,ari3s/portingdb,irushchyshyn/portingdb,fedora-python/portingdb,irushchyshyn/portingdb,fedora-python/portingdb,ari3s/portingdb,irushchyshyn/portingdb,fedora-python/portingdb,irushchyshyn/portingdb,ari3s/portingdb