The original article is here:
https://qa.sqlservercentral.com/steps/stairway-to-sqlclr-level-1-what-is-sqlclr
I made revisions to this in what I believe was the same manner as I did with level 2 of that same Stairway series. However, whereas my revision to Level 2 completely replaced the original Level 2 but kept the same URL, number of reads, ratings, etc, my revision to Level 1 has become a new, second live version of Level 1, with a new URL and no carry-over of reads / ratings (but the "discuss" link to the related forum does point to the original forum):
https://qa.sqlservercentral.com/steps/stairway-to-sqlclr-level-1-what-is-sqlclr-2
Both are publicly accessible. Looking at my author list, the new revision is the most recent entry:
https://qa.sqlservercentral.com/author/solomon-rutzky
while the original is also there, but on page 6:
https://qa.sqlservercentral.com/author/solomon-rutzky/page/6
Take care,
Solomon....