Documenting pushdefault config option

There seem to be 3 variations of the git push command:

1. Use git push origin branchname and always specify the remote and the branch
2. Use git push -u origin branchname on the first push to set origin as the default and then just use git push
3. Set the pushdefault to origin in .git/config and just use git push

The first method is the one suggested in the devguide
(e.g. in the submitting section); the second is also documented in the pushing changes section; the third is apparently somewhat recent and not yet documented.

The pushdefault is configured by adding to .git/config:

[remote]
    pushdefault = origin

Where origin refers to the user's fork of cpython. AFAICT almost all the pushes should go to origin.

Each method has pros and cons:

First method:

• pros: explicit is better than implicit
• cons: longer to type, harder to remember, could get the arg names/order wrong

Second method:

• pros: still explicit but shorter to type for the following pushes
• cons: same as above but only applies to the first push on each branch

Third method:

• pros: easier to remember, shorter to type, works like hg push
• cons: less explicit

The question is: which one should we adopt as the recommended method?

查看 devguide 中链接的 submitting 和 pushing changes 部分，以及 .git/config 中的 pushdefault 示例。比较文档中介绍的三种工作流，确定指南应推荐哪种方法，然后更新相关文档，明确这一选择及其设置方式。