* Cleaning up the whitelist a bit.
* The magic to exclude repeated characters worked 👍
* Every successful run on master now logs its suggested cleanup, e.g. for 5740e197c2 has https://github.com/microsoft/terminal/runs/596271627#step:4:37
* ⚠️ This check-spelling 0.0.15a+ tolerates Windows line endings in the `whitelist.txt` file (another project I touched had some `.gitconfig` magic which required supporting them).
This means that if someone edits the file w/ something that likes Windows line endings, the file will successfully convert (instead of it being ignored and check-spelling complaining about everything). Most likely anyone else who then edits the file will use something that will maintain the line endings.