feat: Add closed contribution process

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.

Author: ADubhlaoich

CLOSED_CONTRIBUTIONS.md

@@ -0,0 +1,53 @@
+# Contributing guidelines for closed content
+
+This document describes the process for authoring "closed content", which is content of a commercially sensitive nature that cannot be publicised before release.
+
+Commercially 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.
+
+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
+```
+
+After you have iterated on the closed content, you can open a PR 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
+```

F5-NGINX-team-notes.md

@@ -1,12 +1,10 @@
 # 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 a functional mirror. We want to do as much of our work as possible in the public repository. 
 
-- Security content, including personally identifying information (PII).
-- Content / features that are not yet ready to be announced.
+Content which cannot be publicised before release is handled slightly differently: please read the [Contributing guidelines for closed content](/CLOSED_CONTRIBUTIONS.md) document.
 
-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.
+Before new content is published at https://docs.nginx.com, it must be commited to this `documentation` repository. 
 
 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.