doc: add maturity level

[ktaborowski]

Move maturity level tables from NCS

CI parameters

Jenkins:
  test-sdk-sidewalk: master
  # To reconfigure functional tests:
  # use GH labels func-* (default is func-commit)
  # or
  # Use YAML Filters. Helper side to set filters: https://tester-pc.nordicsemi.no:8080/test_mgmt
  # Filters (place copied YAML filters here):
  #  - filter1:
  #     board: nrf52

Description

JIRA ticket:

Self review

• There is no commented code.
• There are no TODO/FIXME comments without associated issue ticket.
• Commits are properly organized.
• Change has been tested.
• Tests were updated (if applicable).

[github-actions]

Sample		diff	used	total

Memory usage did not change for any of the samples.

[annwoj]

Suggested change

	Software maturity
	*****************
	In nRF Connect SDK, maturity levels are defined for each feature and component.
	For more details about software maturity levels, see the `nRF Connect SDK software maturity levels documentation <https://docs.nordicsemi.com/bundle/ncs-3.0.0/page/nrf/releases_and_maturity/software_maturity.html>`_.
	For Sidewalk features support, refer to the following page:
	Software maturity
	*****************
	In the nRF Connect SDK, maturity levels are defined for each feature and component.
	For more information about definitions and other support, see the `nRF Connect SDK software maturity levels documentation`_.

Link needs to be added to the links file