Add a NOAA-NCEI example URL to contributor_role_vocabulary?

[mwengren]

Related: ioos/compliance-checker#810

Might not be clear to data providers what Compliance Checker will accept in this field.

Possible NCEI URLs for CI_RoleCode vocabulary:

• https://data.noaa.gov/resources/iso19139/schema/resources/Codelist/gmxCodelists.xml#CI_RoleCode
• https://www.ngdc.noaa.gov/wiki/index.php?title=ISO_19115_and_19115-2_CodeList_Dictionaries#CI_RoleCode

[mwengren]

NERC:

• HTTP: http://vocab.nerc.ac.uk/collection/G04/current/
• HTTPS: https://vocab.nerc.ac.uk/collection/G04/current/

NCEI: Just use the wiki links (not XML link above) via either HTTP|HTTPS:

• HTTP: http://www.ngdc.noaa.gov/wiki/index.php?title=ISO_19115_and_19115-2_CodeList_Dictionaries#CI_RoleCode
• HTTPS: https://www.ngdc.noaa.gov/wiki/index.php?title=ISO_19115_and_19115-2_CodeList_Dictionaries#CI_RoleCode

See: ioos/compliance-checker#810 (comment)

[mwengren]

We added the NERC URL, so this was actually resolved, however, a remaining issue is:

• the description for contributor_role links to an NCEI URL that no longer exists and should be removed.