Add newspaper refs to all articles

[david-allison]

Started in #680

Related: https://github.com/david-allison-1/manx-corpus-search/issues/54

[david-allison]

Missing (skipped)

• [x] Closing address to the Manx Readings and Concert
• [ ] Eam er y Theay (English Only - no Manx in Newspaper)
  • Manx Sun, Saturday, March 28, 1863; Page: 12
• [ ] Gys VAINSHTYR YN HERAL
  • Mona’s Herald, Wednesday, December 12, 1860; Page: 3
• [ ] Letter from the Rev J. T. Clarke
  • unsure about this, doesn't match perfectly
• [ ] 47. Raaue:
  • Mona's Herald, Wednesday, March 09, 1864; Page: 10
• [ ] Slattysn 1867 I
  • Isle of Man Times, Saturday, February 23, 1867; Page 5.