Add intro for primary_file_spec

[rfrenchseti]

• Were any Django, import pipeline, table_schema, or dictionary files modified? Y
  • Database used: opus3_test_200304
  • All Django tests pass: Y
• Were any JavaScript or CSS files modified? N
  • JSHINT run on all affected files: NA
  • Tested on Chrome, Firefox, Safari, and iOS: N (Remember to test all browser sizes)
  • Tested for race conditions (with delayed API calls if applicable): NA

Description of changes:

Added intro paragraph to the primary file spec search widget explaining how to search without using file extensions.

Known problems:

None.

[matthewtiscareno]

Hi Rob. Can I see how this change looks in OPUS?

[matthewtiscareno]

SpecX ==> Spec has different ==> uses different each mission and instrument ==> different data product types, eliminate ==> do not include from ==> in and use ==> and that you use