Currently, the pre-commit hook will output all files that prettier analyzes.
The changed lines are highlighted in the terminal, but this highlighting is not always successful (e.g. we have seen the highlighting disappear when running inside Jenkins)
This sets prettier (when running within pre-commit) to only output changed files
- Prettier support YAML but pre-commit hook was not checking those
files so added file extensions to hooks config.
- Used double-quoted flow scalar style to make the list of file
extensions easier to read. Backslash for regex needed escaping and
backslash each line to prevent YAML including spaces.
- Added alternative markdown file extensions.
