RFR: Section on PRs [v5]

[Jesper Wilhelmsson]

> Some tips for creating pull requests.

Jesper Wilhelmsson has updated the pull request incrementally with two additional commits since the last revision:

 - Merge branch 'pr2' of github.com:JesperIRL/guide into pr2
 - Fixes after review

-------------

Changes:
  - all: https://git.openjdk.java.net/guide/pull/79/files
  - new: https://git.openjdk.java.net/guide/pull/79/files/67993f28..c11d07cf

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=guide&pr=79&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=guide&pr=79&range=03-04

  Stats: 9 lines in 1 file changed: 8 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/guide/pull/79.diff
  Fetch: git fetch https://git.openjdk.java.net/guide pull/79/head:pull/79

PR: https://git.openjdk.java.net/guide/pull/79