Improve gitignore file comments and organization.

[felddy]

🗣 Description

• Add a comment describing what the files does.
• Add sections to organize patterns.
• Add a pattern that developers may use to quickly ignore files private to their development environment.

💭 Motivation and context

I'd like to propose a pattern that we can use to quickly ignore files in our development environments.
I've found that sometimes I have the need for a scratch file, or a configuration that I'm testing locally that I don't want to end up under version control.

I've been using *-mine.*

This allows me to have files like TODO-mine.md, docker-compose-mine.yml, or secrets-mine.json to live locally without fear of them making it into the repo.

A quick Google search didn't turn up any related proposals for something like this. We could also use *-ignoreme.*,*-nocommit.*, *-yourmom.*

Pros:

• Easy to use
• Short and meaningful
• Shouldn't ignore files inadvertently: e.g., hexanitrodiphenylamine.py

Cons:

• Could inadvertently ignore a file: e.g.,land-mine.yml
• Doesn't work with extension-less files : e.g., LICENSE-mine

Alternatives:

• I could just set this in my ~/.gitignore_global file, and then git config --global core.excludesFile ~/.gitignore_global
• (I'll probably do that as well)

🧪 Testing

Works for me!

📷 Screenshots (if appropriate)

✅ Checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• All new and existing tests pass.

[jsf9k]

I don't like this. It's too dangerous, since it could exclude something important.

This feels to me like a personal preference that should be handled in your local global git configuration. As a result I suggest closing this PR unmerged.

"It's a no from me dog."

[felddy]

I don't like this. It's too dangerous, since it could exclude something important.

This feels to me like a personal preference that should be handled in your local global git configuration. As a result I suggest closing this PR unmerged.

"It's a no from me dog."

Yes, It could exclude something important. But that is an easy fix. I'd rather err on the side of excluding something instead of including it.

I'm fine with setting this in my globals if there is no value in this for anyone.
I checked that my IDEs are smart enough to honor that.

I would like to merge the comments still since we do have people using the skeletons as their first interaction with git.
I do not want to abandon this PR entirely.

[hillaryj]

I also like the comments and would like to add them. I don't have a strong preference, but would err on the side of the convenience exclusions as a personal setting.

[jsf9k]

...would err on the side of the convenience exclusions as a personal setting.

👆

[hillaryj]

💬

[dav3r]

👻