Add developer manual for making a pull request

[Wang-yijun]

Add steps to fork, make changes on a branch, and open pull requests to contribute to the GWB.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (bc9dead) 93.55% compared to head (deb2b2a) 93.55%.
Report is 16 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #567   +/-   ##
=======================================
  Coverage   93.55%   93.55%           
=======================================
  Files          92       92           
  Lines        6343     6343           
=======================================
  Hits         5934     5934           
  Misses        409      409           

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[gassmoeller]

Can you add a fourth step that says address the comments that were brought up during the review? Just to make users aware this is not done after opening the PR.

[github-actions]

Benchmark	Main	Feature	Difference (99.9% CI)
Slab interpolation simple none	1.024 ± 0.003 (s=420)	1.025 ± 0.004 (s=461)	-0.1% .. +0.1%
Slab interpolation curved simple none	1.026 ± 0.002 (s=441)	1.025 ± 0.002 (s=439)	-0.1% .. -0.0%
Spherical slab interpolation simple none	1.265 ± 0.004 (s=352)	1.265 ± 0.006 (s=362)	-0.1% .. +0.1%
Slab interpolation simple curved CMS	1.097 ± 0.003 (s=408)	1.097 ± 0.004 (s=415)	-0.1% .. +0.1%
Spherical slab interpolation simple CMS	1.861 ± 0.006 (s=237)	1.860 ± 0.007 (s=249)	-0.1% .. +0.1%
Spherical fault interpolation simple none	1.274 ± 0.004 (s=351)	1.275 ± 0.012 (s=358)	-0.1% .. +0.3%
Cartesian min max surface	2.383 ± 0.015 (s=183)	2.378 ± 0.021 (s=198)	-0.5% .. +0.0%
Spherical min max surface	7.370 ± 0.023 (s=80)	7.364 ± 0.016 (s=45)	-0.2% .. +0.1%

[tjhei]

Concise. I like it!