fixes from pr review

Signed-off-by: Guilherme Eric <guilherme.eric@outlook.com>

.changeset/metal-hairs-build.md

@@ -2,4 +2,4 @@
 '@backstage/plugin-rollbar-backend': patch
 ---
 
-Updated rollbar-backend's README to include clearer instructions on how to install and configure.
+Updated README to include clearer installation instructions on how to install and configure.

plugins/rollbar-backend/README.md

@@ -23,12 +23,13 @@ export default async function createPlugin(
 ): Promise<Router> {
   return await createRouter({
     logger: env.logger,
-    config: env.config
+    config: env.config,
   });
 }
 ```
 
 3. Modify your `packages/backend/src/index.ts` to include:
+
 ```diff
  ...