Restructure template, add configurable description, remove comments

- Remove LoadPriority override from EntryPoint.cs (defaults to Medium)
- Add Description property (was already templated as a literal, now a
  configurable PluginDescription symbol like PluginAuthor)
- Move the buildable project into content/ so CLAUDE.md, .editorconfig,
  and .gitignore never ship in a generated plugin, and the project no
  longer shares its root with them
- Remove the SkipGit symbol and its manual-instructions postAction:
  automatic git init on generation was re-verified impossible (no
  --allow-scripts equivalent on dotnet 10 SDK to bypass the Run Script
  postAction's interactive Y/N gate); VS's own New Project checkbox
  already covers this
- Add content/CLAUDE.md so every generated plugin ships with LabAPI/
  toolchain/code-style context for Claude Code, since no C#/.NET/LabAPI
  Skill exists in the catalog
- Set PluginAuthor/PluginDescription defaultValue to generic "Your
  Name"/"Your Description" placeholders instead of "YourName"/a TODO
  string
- Strip all comments from the .csproj (project code style forbids them)

Verified by generating a project from the reinstalled template and
running dotnet build (0 warnings, 0 errors) after each change.

.template.config/template.json

@@ -10,19 +10,26 @@
   },
   "sourceName": "LabApiPluginTemplate",
   "preferNameDirectory": true,
+  "sources": [
+    {
+      "source": "./content",
+      "target": "./"
+    }
+  ],
   "symbols": {
     "PluginAuthor": {
       "type": "parameter",
       "datatype": "string",
-      "defaultValue": "YourName",
+      "defaultValue": "Your Name",
       "replaces": "YourName",
       "description": "Name used as the plugin's author."
     },
-    "SkipGit": {
+    "PluginDescription": {
       "type": "parameter",
-      "datatype": "bool",
-      "description": "If set, skips printing the reminder to initialize a git repository.",
-      "defaultValue": "false"
+      "datatype": "string",
+      "defaultValue": "Your Description",
+      "replaces": "TODO: describe what this plugin does.",
+      "description": "Short description of what the plugin does."
     }
   },
   "primaryOutputs": [
@@ -36,15 +43,6 @@
       ],
       "actionId": "210D431B-A78B-4D2F-B762-4ED3E3EA9025",
       "continueOnError": true
-    },
-    {
-      "condition": "(!SkipGit)",
-      "description": "This project is not a git repository yet.",
-      "manualInstructions": [
-        { "text": "Run 'git init && git add -A && git commit -m \"Initial commit\"'" }
-      ],
-      "actionId": "AC1156F7-BB77-4DB8-B28F-24EEBCCA1E5C",
-      "continueOnError": true
     }
   ]
 }