quarto create extension support

Author: cscheid

src/command/create/artifacts/extension.ts

@@ -40,6 +40,7 @@ const kExtensionTypes: Array<string | ExtensionType> = [
   },
   { name: "journal format", value: "journal", openfiles: ["template.qmd"] },
   { name: "custom format", value: "format", openfiles: ["template.qmd"] },
+  { name: "metadata", value: "metadata", openfiles: [] },
 ];
 
 const kExtensionSubtypes: Record<string, string[]> = {

src/resources/create/extensions/metadata/.gitignore

@@ -0,0 +1,3 @@
+*.html
+*.pdf
+*_files/

src/resources/create/extensions/metadata/README.ejs.md

@@ -0,0 +1,22 @@
+# <%= title %> Extension For Quarto
+
+_TODO_: Add a short description of your extension.
+
+## Installing
+
+_TODO_: Replace the `<github-organization>` with your GitHub organization.
+
+```bash
+quarto add <github-organization>/<%= filesafename %>
+```
+
+This will install the extension under the `_extensions` subdirectory.
+If you're using version control, you will want to check in this directory.
+
+## Using
+
+_TODO_: Describe how to use your extension.
+
+## Example
+
+Here is the source code for a minimal example: [example.qmd](example.qmd).

src/resources/create/extensions/metadata/_extensions/qstart-filesafename-qend/_extension.ejs.yml

@@ -0,0 +1,8 @@
+title: <%= title %>
+author: <%= author %>
+version: <%= version %>
+quarto-required: ">=<%= quartoversion %>"
+contributes:
+  metadata:
+    project:
+      # your per-project metadata goes here