Convert contributing guide to Markdown

Signed-off-by: lucperkins <[email protected]>

Author: lucperkins

.editorconfig

@@ -9,7 +9,3 @@ indent_style = tab
 [*.{html,js,json,md,sass,yaml}]
 indent_style = space
 indent_size = 2
-
-[*.py]
-indent_style = space
-indent_size = 4

assets/sass/style.sass

@@ -171,6 +171,9 @@ $colors: mergeColorMaps(("secondary": ($secondary, $white), "twitter-blue": ($tw
       max-height: 5rem
 
 .content
+  .button
+    margin: 1rem 0
+
   @for $i from 1 through 6
     h#{$i}
       &::before

content/contribute.md

@@ -0,0 +1,31 @@
+---
+title: Contributing to gRPC
+---
+
+To contribute to gRPC documentation, please fork the [gRPC repository on GitHub](https://github.com/grpc/grpc.io) and start submitting pull requests.
+
+## Contribute guidelines for gRPC
+
+We welcome contributions to any of our three core repositories:
+
+* [gRPC](https://github.com/grpc/grpc)
+* [gRPC Java](https://github.com/grpc/grpc-java)
+* [gRPC Go](https://github.com/grpc/grpc-go)
+
+{{< button text="View guidelines" url="https://github.com/grpc/grpc/blob/master/CONTRIBUTING.md" >}}
+
+## Contribution guidelines for the gRPC Ecosystem
+
+The [gRPC Ecosystem](https://github.com/grpc-ecosystem/) is a different organization where we collect and curate valuable integrations of other projects with gRPC. You can propose a new project for it by filling out the **Propose new project** form.
+
+{{< button text="View guidelines" url="https://github.com/grpc/grpc-contrib/blob/master/CONTRIBUTING.md" >}}
+
+## Edit our site on GitHub
+
+Click the below button to visit the repo for our site. You can then click the "Fork" button in the upper-right area of the screen to create a copy of our site on your GitHub account called a "fork." Make any changes you want in your fork, and when you are ready to send those changes to us, go to the index page for your fork and click **New Pull Request** to let us know about it.
+
+{{< button text="Browse this site's source code" url="https://github.com/grpc/grpc.io" >}}
+
+## Being a member of the gRPC organization on github
+
+Being an organization member is not required for the vast majority of the contributions. Membership is required for certain administrative tasks such as accepting a pull request, or closing issues. If you wish to be part of the gRPC organization on github, please [get in touch with us](/community). Please note that in order to be part of the organization, your GitHub account needs to have [two-factor authentication enabled](https://help.github.com/articles/securing-your-account-with-two-factor-authentication-2fa/).

content/contribute/index.html

@@ -0,0 +1,11 @@
+{{ $text := .Get "text" }}
+{{ $url  := .Get "url" }}
+{{ $isExternal := hasPrefix $url "http" }}
+<a class="button is-primary is-outlined" href="{{ $url }}"{{ if $isExternal }} target="_blank"{{ end }}>
+  <span class="icon">
+    <i class="fas fa-sm fa-external-link-alt"></i>
+  </span>
+  <span>
+    {{ $text }}
+  </span>
+</a>