Update gitdocs (#2500)

docs/helpful-hints.md

@@ -11,3 +11,7 @@ You can view the previews at (for example) `http://localhost:3000/rails/mailers/
 1. Install gitdocs `npm install -g gitdocs@next`
 1. Serve it `gitdocs serve`
 1. Visit `http://localhost:8000`
+
+## Caching
+
+- [DEV Notes: Don't Forget To Clear Cache!](https://dev.to/jess/dev-notes-don-t-forget-to-clear-cache-962)

docs/installation/readme.md

@@ -6,8 +6,25 @@ items:
   - windows.md
 ---
 
-# Detailed Installation Guides
+# Installation Guides For macOS, Linux, and Windows
 
-These are the guides for installing the app on different operating systems.
+Below are the guides for installing the app on different operating systems.
 
 These guides could be incorrect or outdated. If you come across anything that needs to be changed, make a PR! Thanks!
+
+# GitPod
+
+You can also [spin up a "local" instance of DEV in the cloud with GitPod (It's incredibly simple)](https://dev.to/ben/spin-up-a-local-instance-of-dev-in-the-cloud-with-gitpod-it-s-incredibly-simple-pij): https://gitpod.io/#https://github.com/thepracticaldev/dev.to
+
+# Docker [Beta]
+
+Our docker implementation is incomplete and may not work smoothly. Please kindly report any issues and any contribution is welcomed!
+
+1. Install `docker` and `docker-compose`
+1. `git clone git@github.com:thepracticaldev/dev.to.git`
+1. Set environment variables above as described in the "Basic Installation"
+1. run `docker-compose build`
+1. run `docker-compose run web rails db:setup`
+1. run `docker-compose run web yarn install`
+1. run `docker-compose up`
+1. That's it! Navigate to `localhost:3000`