closes#1510
The change in `create_highlighted_versions.py` fixes a "unknown theme
"'1337'" warning. The single quotes were wrong. `bat` was always falling
back to the default theme, so let's use that for now.
#1244 Slightly optimized create_highlighted_versions.py so that it won't walk the source path when it should be skipping the file
#1244 Updated README.md in plaintext source folder
#1244 Added extra option loading from `bat_options` file in directory and significantly reduced size of plaintext source
#1244 Updated create_highlighted_versions.py to ignore README.md files and use the --show-all option for manually-defined binary files
#1244 Updated plaintext file with command
bat -A --no-config --style=plain --color=always --theme='1337' --italic-text=always src/Plaintext/plaintext.txt > highlighted/Plaintext/plaintext.txt
#1244 Added example plaintext file
