Add doc comments to variables and labels

[psoukie]

Is your feature request related to a problem? Please describe.
Currently, you can add a comment to the function using a semicolon on the line above the function declaration, and it appears as a tooltip when you hover over the function name in the editor.

Describe the solution you'd like
Extend this functionality to variables, so that an in-line comment after the variable definition, or on the line above it, also appears in the tooltip.

[rlitwiller89]

Could you also do this for labels too?