repo-tools: Quote markdown headers

Signed-off-by: Johan Haals <johan.haals@gmail.com>

.changeset/thirty-llamas-whisper.md

@@ -0,0 +1,5 @@
+---
+'@backstage/repo-tools': patch
+---
+
+Updated api docs generation to be compatible with Docusaurus 2-alpha and 2.x.

packages/repo-tools/src/commands/api-reports/api-extractor.ts

@@ -840,7 +840,9 @@ export async function buildDocs({
           context.writer.writeLine('---');
           for (const [name, value] of Object.entries(node.values)) {
             if (value) {
-              context.writer.writeLine(`${name}: ${value}`);
+              context.writer.writeLine(
+                `${name}: "${String(value).replace(/\"/g, '')}"`,
+              );
             }
           }
           context.writer.writeLine('---');