Remove Travis CI and Update Docs (#5591)

* chore: remove travis-ci

* chore: replace travis-ci docs with github actions

Author: SethFalco

Diff for: .github/PULL_REQUEST_TEMPLATE.md

@@ -17,6 +17,6 @@ Add resource(s) | Remove resource(s) | Add info | Improve repo
 - [ ] Put lists in alphabetical order, correct spacing.
 - [ ] Add needed indications (PDF, access notes, under construction)
 
-## Followup
+## Follow-up
 
-- Check the output of Travis-CI for linter errors!
+- Check the status of GitHub Actions and resolve any reported warnings!

Diff for: .travis.yml

@@ -20,7 +20,7 @@ By contributing you agree to respect the [Code of Conduct](https://github.com/Eb
 
 4. Make sure to follow the [guidelines below](#guidelines) and respect the [Markdown formatting](#formatting) of the files.
 
-5. Travis CI will run tests to make sure your lists are alphabetized and formatting rules are followed. Be sure to check that your changes pass the tests.
+5. GitHub Actions will run tests to make sure your lists are alphabetized and formatting rules are followed. Be sure to check that your changes pass the tests.
 
 ### Guidelines
 - make sure a book is free. Double-check if needed. It helps the admins if you comment in the PR as to why you think the book is free.
@@ -204,7 +204,7 @@ If you can print it out and retain its essence, it's not an Interactive Tutorial
 
 ### Automation
 
-- Formatting rules enforcement is automated via [Travis CI](https://travis-ci.com) using [fpb-lint](https://github.com/vhf/free-programming-books-lint) (see [.travis.yml](.travis.yml))
+- Formatting rules enforcement is automated via [GitHub Actions](https://github.com/features/actions) using [fpb-lint](https://github.com/vhf/free-programming-books-lint) (see [.github/workflows/fpb-lint.yml](.github/workflows/fpb-lint.yml))
 - URL validation uses [awesome_bot](https://github.com/dkhamsing/awesome_bot)
 - To trigger URL validation, push a commit that includes a commit message containing `check_urls=file_to_check`:
 

Diff for: CONTRIBUTING.md

@@ -12,6 +12,6 @@ Welcome to Free-Programming-Books! We welcome new contributors; even those makin
 
 Don't hesitate to ask questions; every contributor started with a first PR. You could be our thousandth!
 
-Even if you're an experienced open source contributor, there are things that might trip you up. Once you've submitted your PR, Travis-CI will run a linter, often finding little issues with spacing or alphabetization. If you get a green button, everything is ready for review, but if not, click on the travis link to find out what the linter didn't like. Fix the problem and add a commit to your PR.
+Even if you're an experienced open source contributor, there are things that might trip you up. Once you've submitted your PR, GitHub Actions will run a linter, often finding little issues with spacing or alphabetization. If you get a green button, everything is ready for review, but if not, click "Details" under the check that failed to find out what the linter didn't like. Fix the problem and add a commit to your PR.
 
 Finally, if you're not sure that the resource you want to add is appropriate for Free-Programming-Books, read through the guidelines in [CONTRIBUTING](CONTRIBUTING.md).