Something unknown added this to my htaccess. What to make of it?

Today I noticed that the .htaccess file in my public_html root was modified a couple of months ago.

Before every RewriteRule line, some bot or somebody has added the following three lines:

RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
# lines above were inserted above each rewrite such as the following
RewriteRule ^home/? /index.html     [QSA,END,NC]

I also noticed that I had a public_html/.well-known/acme-challenge/ empty directory. I have two questions.

1. What should I make of this?
2. What effect do the rewrite conditions have? My rewrites still seem to work as before.

Update

It seems to have to do with Let's Encrypt TLS cert auto-renewal, so the folder was probably created by the certification bot. But why do such a hatch job of my .htaccess? the trio of lines I pointed out appears, as I said, before every rewrite. So it adds a lot of bloat and confusion to the file.