git-fast-export: add page

[msaf9]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

[tldr-bot]

The build for this PR failed with the following error(s) at commit
1683995f6129d050a115cc5c7850d4f40927f44b:

pages/common/git-fast-export.md:22: TLDR005 Example descriptions should end in a colon with no trailing characters

Please fix the error(s) and push again.

[Managor]

What doesgit fast-export without any extra arguments do?

[msaf9]

If we run git fast-export without any arguments, Git doesn’t know what commits or refs to export, so it simply shows the usage/help message, like:

usage: git fast-export [<rev-list-opts>]

[Managor]

I assume you pushed that page to the wrong branch

[msaf9]

I just added one more page, but forgot about the current in-progress PR.

[Managor]

Why do the output files all have different names and extensions?

[msaf9]

I want to demonstrate that we can export to various file formats and use different file names to prevent confusion.

[Managor]

Does the export format get defined by simply changing the output extension?

[msaf9]

No, the file extension in git fast-export doesn’t affect the export format at all.

git fast-export writes a plain-text stream that describes the full commit history in a special format defined by Git.

[Managor]

I see you accidentally used your main branch as the one you filed the pull request from. I'll help you out and call for others to quickly review this PR so that you can nuke your repo and start in a clean branch

[msaf9]

Thank you so much!

[SpikeTheDragon40k]

Lgtm! Thank you for the contribution!

[acuteenvy]

Thanks!