Add cvar-standardize.sh script to qcsrc/tools/

Add cvar-standardize.sh script to qcsrc/tools/

Added a bash script to somewhat-standardize cvar descriptions so that they're no longer a huge mess.
Will run the script in the following commit.
Rules this applies are outlined by L114-L122:
- remove_ending_period "${file}"
- change_colons_to_equals "${file}"
- quote_options "${file}"
- uppercase_notes "${file}"
- lowercase_after_notes "${file}"
- lowercase_option_first_letter "${file}"
- lowercase_first_letter "${file}"
- lowercase_after_sentences "${file}"
- # Americanizing spelling will have to be done manually
Since it's not perfect, cvar lines can be "opted out" from the script by appending "// script-ignore".