fix: vendor all .html files (ethereumjs#566)

Follow up for ethereumjs#562 

Apologies, I don't know if this is testable locally. For the previous PR I was missing a glob pattern, but I assume all HTML files are auto-generated here so it's probably easier to just mark them all as such

Co-authored-by: Scotty <[email protected]>
Co-authored-by: acolytec3 <[email protected]>

Author: 3 people

.gitattributes

@@ -1 +1 @@
-packages/portalnetwork/docs/ linguist-vendored
+*.html linguist-vendored