Add ability to add "Sections" in code

[martindsouza]

Sometimes I want to group common functions together and provide an overview of these functions. Example is Logger. All the functions (log, log_warning, log_error, etc) all have the same APIs. A brief description for all of them is warranted.

Currently the only way to do this is put all the "general" documentation in the first API call. Instead I'd like the ability to add a level "higher" than a function.

The TOC should look like this:

• Types
• Constants
• Main Logger Functions
  • log
  • log_warning
  • ...
• Utility Functions
  • to_char
    etc...

The documentation would look like this:

...

Main Logger Functions

Some full description along with examples (no special tags)

log

...

Some things to think of:

• What tags will we use? (ex: @header)?
• Could we leverage this with package header comments (there's a ticket for this as well The Package Purpose Documentation gets deleted with SQL-Developer #65)