Add custom plugins

[xbourguignon (Xavier Bourguignon)]

Hi Sean,

No third-party plugins are installed on sonarCloud since we need to master the whole stack to provide the best experience.

That being said, if your CI generates reports for Findbugs, ESLint, & co, you can import the results in SonarCloud. Please follow the documentation here:

• https://docs.sonarqube.org/display/PLUG/Importing+SpotBugs%2C+FindSecBugs%2C+PMD%2C+Checkstyle+Issues+Reports
• https://docs.sonarqube.org/display/PLUG/Importing+ESLint+Issues+Reports