Move plugins to manifest, pin Docker version, add Makefile

- Add plugins.txt listing all plugins for reproducible installs
- Add Makefile with setup/start/stop/install-plugins targets
- Remove user/plugins/ from git tracking
- Pin Docker image to 1.7.49.5-ls244

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/form/README.md

@@ -1,41 +0,0 @@
-# Grav Form Plugin
-
-The **form plugin** for [Grav](https://github.com/getgrav/grav) adds the ability to create and use forms.  This is currently used extensively by the **admin** and **login** plugins.
-
-# Installation
-
-The form plugin is easy to install with GPM.
-
-```
-$ bin/gpm install form
-```
-
-# Configuration
-
-Simply copy the `user/plugins/form/form.yaml` into `user/config/plugins/form.yaml` and make your modifications.
-
-```
-enabled: true
-```  
-
-# How to use the Form Plugin
-
-The Learn site has two pages describing how to use the Form Plugin:
-- [Forms](https://learn.getgrav.org/forms)
-- [Add a contact form](https://learn.getgrav.org/forms/forms/example-form)
-
-# Using email
-
-Note: when using email functionality in your forms, make sure you have configured the Email plugin correctly. In particular, make sure you configured the "Email from" and "Email to" email addresses in the Email plugin with your email address.
-
-# NOTES:
-
-As of version **Form 6.0.0** forms are no longer initialized before caching, but when the form is requested. This has been done to make dynamic forms to work better with caching. There may be some backward compatibility issues for logic that modifies pages with forms as the modification doesn't happen without accessing the form first.
-
-As of version **Form 5.0.0** Grav 1.7+ is required.
-
-As of version **Form 4.0.6**, form labels are now being output with the `|raw` filter.  If you wish to show HTML in your form label, ie `Root Folder <root>`, then you need to escape that in your form definition:
-
-```yaml
-label: Root Folder &lt;root&gt;
-```