Remove prompts from website

Remove the prompts page, navigation link, homepage card, and all
references to prompts across the website source code. The repo no
longer contains prompt files, so the website should not reference them.

Files removed:
- website/src/pages/prompts.astro
- website/src/scripts/pages/prompts.ts

Files updated:
- BaseLayout.astro: remove nav link and update description
- index.astro: remove prompts card and update text
- llms.txt.ts: remove prompts import and section
- plugins.astro: update description text
- utils.ts: remove prompt type from install config, icons, labels
- pages/index.ts: remove prompts from counts
- modal.ts: update JSDoc comment

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

website/src/scripts/utils.ts

@@ -15,10 +15,6 @@ const VSCODE_INSTALL_CONFIG: Record<
     baseUrl: "https://aka.ms/awesome-copilot/install/instructions",
     scheme: "chat-instructions",
   },
-  prompt: {
-    baseUrl: "https://aka.ms/awesome-copilot/install/prompt",
-    scheme: "chat-prompt",
-  },
   agent: {
     baseUrl: "https://aka.ms/awesome-copilot/install/agent",
     scheme: "chat-agent",
@@ -93,7 +89,7 @@ export async function copyToClipboard(text: string): Promise<boolean> {
 
 /**
  * Generate VS Code install URL
- * @param type - Resource type (agent, prompt, instructions)
+ * @param type - Resource type (agent, instructions)
  * @param filePath - Path to the file
  * @param insiders - Whether to use VS Code Insiders
  */
@@ -227,7 +223,6 @@ export function truncate(text: string | undefined, maxLength: number): string {
  */
 export function getResourceType(filePath: string): string {
   if (filePath.endsWith(".agent.md")) return "agent";
-  if (filePath.endsWith(".prompt.md")) return "prompt";
   if (filePath.endsWith(".instructions.md")) return "instruction";
   if (/(^|\/)skills\//.test(filePath) && filePath.endsWith("SKILL.md"))
     return "skill";
@@ -246,7 +241,6 @@ export function getResourceType(filePath: string): string {
 export function formatResourceType(type: string): string {
   const labels: Record<string, string> = {
     agent: "🤖 Agent",
-    prompt: "🎯 Prompt",
     instruction: "📋 Instruction",
     skill: "⚡ Skill",
     hook: "🪝 Hook",
@@ -261,7 +255,6 @@ export function formatResourceType(type: string): string {
 export function getResourceIcon(type: string): string {
   const icons: Record<string, string> = {
     agent: "🤖",
-    prompt: "🎯",
     instruction: "📋",
     skill: "⚡",
     hook: "🪝",