leave other tags alone in PlainTextFilter
leave other tags alone in PlainTextFilter

@rtomayko's original comment:

  Yeah. I've wanted this for a while. A good place to start would be with
  a `<link rel=permalink href=...>` tag in the head. We do that for patch
  and diff URLs today.

The email I received (notice the <link> is gone):

  Yeah. I've wanted this for a while. A good place to start would be with
  a `` tag in the head. We do that for patch and diff URLs today.

nono/html-pipeline-linuxfr,terracatta/html-pipeline,github/html-pipeline,kbrock/html-pipeline,charliesome/html-pipeline,moskvax/html-pipeline,github/html-pipeline,gjtorikian/html-pipeline,kbrock/html-pipeline,moskvax/html-pipeline,jch/html-pipeline,gjtorikian/html-pipeline,jch/html-pipeline,tricknotes/html-pipeline,terracatta/html-pipeline