Add Ironware model notes for 0910 firmware

[dlehman83]

Pre-Request Checklist

• [x ] Passes rubocop code analysis (try rubocop --auto-correct)
• [ ] Tests added or adapted (try rake test)
• [X ] Changes are reflected in the documentation
• [ ] User-visible changes appended to CHANGELOG.md

Description

Updated documentation with model notes for Ruckus ICX switches running 0910 firmware to support user and password at the enable prompt.

Ideally the code in the notes can be included in an update model file in the future.

should close #2907

[robertcheramy]

Is it possible to integrate this directly in lib/oxidized/model/ironware.rb, so that it works with all firmware versions? It should be possible to check if enableuser is defined and change the behavior only then.

The support of the new firmware should be documented in CHANGELOG.md.