feat(dotfiles): add custom variable for the dotfiles parameter description (#151)

## Description

When passing in custom dotfiles URIs, the format for those (`git@...` vs
`https://...`) are going to be different for different environments, and
admins are going to want to give their developers particular
instructions. This PR makes the parameter `description` customizable so
that we can change the default description a developer sees.

---

## Type of Change

- [ ] New module
- [ ] Bug fix
- [x] Feature/enhancement
- [ ] Documentation
- [ ] Other

---

## Module Information

<!-- Delete this section if not applicable -->

**Path:** `registry/coder/modules/dotfiles`  
**New version:** `v1.2.0`  
**Breaking change:** [ ] Yes [X] No

---

## Testing & Validation

- [X] Tests pass (`bun test`)
- [X] Code formatted (`bun run fmt`)
- [x] Changes tested locally

---------

Co-authored-by: DevCats <christofer@coder.com>

registry/coder/modules/dotfiles/README.md

@@ -19,7 +19,7 @@ Under the hood, this module uses the [coder dotfiles](https://coder.com/docs/v2/
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.1.0"
+  version  = "1.2.0"
   agent_id = coder_agent.example.id
 }
 ```
@@ -32,7 +32,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.1.0"
+  version  = "1.2.0"
   agent_id = coder_agent.example.id
 }
 ```
@@ -43,7 +43,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.1.0"
+  version  = "1.2.0"
   agent_id = coder_agent.example.id
   user     = "root"
 }
@@ -55,14 +55,14 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.1.0"
+  version  = "1.2.0"
   agent_id = coder_agent.example.id
 }
 
 module "dotfiles-root" {
   count        = data.coder_workspace.me.start_count
   source       = "registry.coder.com/coder/dotfiles/coder"
-  version      = "1.1.0"
+  version      = "1.2.0"
   agent_id     = coder_agent.example.id
   user         = "root"
   dotfiles_uri = module.dotfiles.dotfiles_uri
@@ -77,7 +77,7 @@ You can set a default dotfiles repository for all users by setting the `default_
 module "dotfiles" {
   count                = data.coder_workspace.me.start_count
   source               = "registry.coder.com/coder/dotfiles/coder"
-  version              = "1.1.0"
+  version              = "1.2.0"
   agent_id             = coder_agent.example.id
   default_dotfiles_uri = "https://github.com/coder/dotfiles"
 }

registry/coder/modules/dotfiles/main.tf

@@ -26,6 +26,12 @@ variable "agent_id" {
   description = "The ID of a Coder agent."
 }
 
+variable "description" {
+  type        = string
+  description = "A custom description for the dotfiles parameter. This is shown in the UI - and allows you to customize the instructions you give to your users."
+  default     = "Enter a URL for a [dotfiles repository](https://dotfiles.github.io) to personalize your workspace"
+}
+
 variable "default_dotfiles_uri" {
   type        = string
   description = "The default dotfiles URI if the workspace user does not provide one"
@@ -64,7 +70,7 @@ data "coder_parameter" "dotfiles_uri" {
   display_name = "Dotfiles URL"
   order        = var.coder_parameter_order
   default      = var.default_dotfiles_uri
-  description  = "Enter a URL for a [dotfiles repository](https://dotfiles.github.io) to personalize your workspace"
+  description  = var.description
   mutable      = true
   icon         = "/icon/dotfiles.svg"
 }