Add default file type for .html and fix default value for category in tfx extension init.

Author: T-Hugs

app/exec/extension/_lib/vsix-manifest-builder.ts

@@ -42,6 +42,7 @@ export class VsixManifestBuilder extends ManifestBuilder {
 		".eot": "application/vnd.ms-fontobject",
 		".gif": "image/gif",
 		".hbs": "text/x-handlebars-template",
+		".html": "text/html",
 		".jpeg": "image/jpeg",
 		".jpg": "image/jpeg",
 		".js": "application/javascript",

app/exec/extension/init.ts

@@ -324,7 +324,7 @@ export class ExtensionInit extends extBase.ExtensionBase<InitResult> {
 			.set("name", extensionName)
 			.set("version", "1.0.0")
 			.set("description", "Azure DevOps Extension")
-			.set("categories", ["Other"]);
+			.set("categories", ["Azure Repos", "Azure Boards", "Azure Pipelines", "Azure Test Plans", "Azure Artifacts"]);
 
 		const newPackageJson = jsonInPlace(packageJsonContents)
 			.set("repository.url", "")