feat: Add closed contribution process (#316)

This commit adds a new document to explain the closed contribution
process. As part of the changes, related content is updated from the
existing documentation specific to F5 employees, decoupling this
particular use case from general guidance.

At a future point, both documents may be reorganised into alternate
files as part of peripheral efforts to document ways of working.

Co-authored-by: Mike Jang <[email protected]>

Author: ADubhlaoich

CLOSED_CONTRIBUTIONS.md

@@ -0,0 +1,67 @@
+# Contributing guidelines for closed content
+
+This document describes the process for authoring "closed content", which is content of a sensitive nature that cannot be publicised before release.
+
+Sensitive content might include:
+
+- Security content, including personally identifying information (PII).
+- Content / features that are not yet ready to be announced.
+
+We work in public by default, so this process should only be used on a case by case basis by F5 employees. For standard content releases, review the [Contributing guidelines](/CONTRIBUTING.md)
+
+## Overview
+
+This repository (https://github.com/nginx/documentation) is where we work by default. It has a one-way sync to an internal repository, used for closed content.
+
+The process is as follows:
+
+- Create a branch with the prefix `internal/` in the closed repository
+- Open a pull request in the closed repository to get previews and request feedback
+- Once all stakeholders are happy with changes, close the pull request in the closed repository
+- Push the changes to the open (public) repository by adding the closed repository as a remote
+- Open a new pull request in the open repository, where it can be merged
+
+You can get the URL through our internal communication channels: it will be represented in the following steps as `<closed-URL>`.
+
+To create closed content, first clone the internal repository:
+
+`git clone [email protected]:<closed-url>.git`
+
+Change into this new directory:
+
+`cd <closed-url>`
+
+Check out the `documentation` branch:
+
+`git checkout documentation`
+
+Create a feature branch, **ensuring that you prefix all branch names with `internal/`**:
+
+`git checkout -b internal/feature`
+
+You can then continue on as normal:
+
+```bash
+# Make documentation changes
+git add .
+git commit
+git push
+```
+
+Open a pull request when you are ready to receive feedback from stakeholders.
+
+After any iterative work, close the pull request. Since the closed repository is a mirror of the open one, we do not merge changes to it.
+
+You should instead open a pull request in the main repository by adding the closed repository as a remote.
+
+```bash
+git clone [email protected]:nginx/documentation.git
+cd documentation
+git add remote internal [email protected]:<closed-url>.git
+git fetch internal internal/feature
+git checkout -b feature
+git merge internal/internal/feature
+git push origin feature
+```
+
+After the content changes have been merged in the open repository, they will synchronize back to the closed repository.

F5-NGINX-team-notes.md

@@ -1,17 +1,14 @@
 # For F5/NGINX Employees
 
-This repository is a functional mirror. We want to do as much of our work as possible in the
-public repository. However, if you are working with:
+This repository is public, and we do as much of our work as possible in the public as a commitment to open source.
 
-- Security content, including personally identifying information (PII).
-- Content / features that are not yet ready to be announced.
+Before new content is published at https://docs.nginx.com, it must be committed to this `documentation` repository. 
 
-Before new content is published at https://docs.nginx.com, it must be written to this `documentation` repository. After you get approvals in the internal `docs` repository, you'll need to create a _second_ pull request in this open `documentation` repository.
+If you are an F5 employee unable to assign yourself as an owner of an issue or a reviewer of a pull request, ask a member of the NGINX documentation team for help.
 
-If you are unable to assign yourself as an owner of an issue or a reviewer of a pull request, and are an employee of F5, ask a member of the NGINX documentation team for help.
+If your content cannot be publicized before release, it is handled differently: read the [Contributing guidelines for closed content](/CLOSED_CONTRIBUTIONS.md) document.
 
-We encourage you to work with community contributors. If you participate in
-PRs, issues, discussions, and more, follow these guidelines:
+We encourage you to work with community contributors. If you participate in PRs, issues, discussions, and more, follow these guidelines:
 
 - Follow the [Code of Conduct](./CODE_OF_CONDUCT.md).
 - Be helpful. We want to encourage people who contribute to continue.