r2e: add page

[samuel-w]

• The page (if new), does not already exist in the repo.
• The page is in the correct platform directory (common/, linux/, etc.)
• The page has 8 or fewer examples.
• The PR title conforms to the recommended templates.
• The page follows the content guidelines.
• The page description includes a link to documentation or a homepage (if applicable).

Part of #3689

[tldr-bot]

The build for this PR failed with the following error(s):

Error: Parse error on line 5:
...s2email/rss2email.> Requires a configu
---------------------^
Expecting 'TEXT', 'DASH', 'BACKTICK', got 'GREATER_THAN'

Please fix the error(s) and push again.

[tldr-bot]

The build for this PR failed with the following error(s):

pages/common/r2e.md:4: TLDR004 Command descriptions should end in a period
pages/common/r2e.md:6: TLDR005 Example descriptions should end in a colon
pages/common/r2e.md:10: TLDR005 Example descriptions should end in a colon
pages/common/r2e.md:14: TLDR005 Example descriptions should end in a colon
pages/common/r2e.md:18: TLDR005 Example descriptions should end in a colon
pages/common/r2e.md:22: TLDR005 Example descriptions should end in a colon

Please fix the error(s) and push again.

[sbrl]

Thanks for the new page, @samuel-w! I've left some comments below for you to review.

[einverne]

Thank you @samuel-w for this new page. It looks good to me.

[sbrl]

Thanks, @samuel-w :D