message: Update sonarqube plugin's README.md to reflect recent changes
  No more use for proxy configuration
  Optional instance name in project annotations
diff: @@ -33,50 +33,14 @@ yarn add --cwd packages/app @backstage/plugin-sonarqube
  );
  ```
  -3. Add the proxy config:
  -
  - Provide a method for your Backstage backend to get to your SonarQube API end point. Add configuration to your `app-config.yaml` file depending on the product you use. Make sure to keep the trailing colon after the `SONARQUBE_TOKEN`, it is required to call
  - the Web API (see [docs](https://docs.sonarqube.org/latest/extend/web-api/)).
  -
  -**SonarCloud**
  -
  -```yaml
  -proxy:
  - '/sonarqube':
  - target: https://sonarcloud.io/api
  - allowedMethods: ['GET']
  - # note that the colon after the token is required
  - auth: '${SONARQUBE_TOKEN}:'
  - # Environmental variable: SONARQUBE_TOKEN
  - # Fetch the sonar-auth-token from https://sonarcloud.io/account/security/
  -```
  -
  -**SonarQube**
  -
  -```yaml
  -proxy:
  - '/sonarqube':
  - target: https://your.sonarqube.instance.com/api
  - allowedMethods: ['GET']
  - # note that the colon after the token is required
  - auth: '${SONARQUBE_TOKEN}:'
  - # Environmental variable: SONARQUBE_TOKEN
  - # Fetch the sonar-auth-token from https://sonarcloud.io/account/security/
  -
  -sonarQube:
  - baseUrl: https://your.sonarqube.instance.com
  -```
  -
  -4. Get and provide `SONARQUBE_TOKEN` as an env variable (https://sonarcloud.io/account/security or https://docs.sonarqube.org/latest/user-guide/user-token/).
  -
  -5. Run the following commands in the root folder of the project to install and compile the changes.
  +3. Run the following commands in the root folder of the project to install and compile the changes.
  ```yaml
  yarn install
  yarn tsc
  ```
  -6. Add the `sonarqube.org/project-key` annotation to the `catalog-info.yaml` file of the target repo for which code quality analysis is needed.
  +4. Add the `sonarqube.org/project-key` annotation to the `catalog-info.yaml` file of the target repo for which code quality analysis is needed.
  ```yaml
  apiVersion: backstage.io/v1alpha1
  @@ -86,9 +50,11 @@ metadata:
  description: |
  Backstage is an open-source developer portal that puts the developer experience first.
  annotations:
  - sonarqube.org/project-key: YOUR_PROJECT_KEY
  + sonarqube.org/project-key: YOUR_INSTANCE_NAME/YOUR_PROJECT_KEY
  spec:
  type: library
  owner: CNCF
  lifecycle: experimental
  ```
  +
  +`YOUR_INSTANCE_NAME/` is optional and will query the default instance if not provided.
  