Miscellaneous documentation fixes
This PR contains miscellaneous fixes & improvements for documentation:
- fixes for code snippets formatting, like,
https://zeppelin.apache.org/docs/0.8.0-SNAPSHOT/setup/security/shiro_authentication.html#apply-multiple-roles-in-shiro-configuration
- fixes syntax
Miscellaneous documentation fixes
### What is this PR for?
This PR contains miscellaneous fixes & improvements for documentation:
- fixes for code snippets formatting, like,
https://zeppelin.apache.org/docs/0.8.0-SNAPSHOT/setup/security/shiro_authentication.html#apply-multiple-roles-in-shiro-co
