migrate site content: contributing docs (#4709)

* migrate contributing docs

* modifies weight for ordering

* updates links and info based on feedback

* removes broken powershell link

* Update site/content/en/contribute/windows/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

* Update site/content/en/contribute/windows/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

* Update site/content/en/contribute/mac/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

* Update site/content/en/contribute/howitworks/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

* Update site/content/en/contribute/howitworks/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

* simplify build explanation

* removes windows docs

* removes community - duplicate

* update the tooling instructions

* point to proposal docs

* Update site/content/en/contribute/howitworks/_index.md

Co-authored-by: Katrina Verey <kn.verey@gmail.com>

site/content/en/contribute/mac/_index.md

@@ -0,0 +1,22 @@
+---
+title: "MacOS Dev Guide"
+linkTitle: "MacOS Dev Guide"
+type: docs
+weight: 50
+description: >
+    How to develop on MacOS
+---
+
+First install the tools to build and run tests
+
+### Install go 1.18
+
+[Instructions](https://golang.org/doc/install)
+
+Add `go` to your PATH
+
+### Install tools
+
+```sh
+make install-tools
+```