Exclude more links in Link Checker (#1017)

Exclude three links in the Link Checker:

- hackmd.io/@pygmt (Invalid mail address: hackmd.io/@pygmt) (lychee is not doing well with @ signs)
- zenodo.org/badge/DOI/10.5281/zenodo [404 Not Found]
- doi.org/10.5281/zenodo [404 Not Found]

Author: seisman

.github/workflows/check-links.yml

@@ -32,6 +32,9 @@ jobs:
         args: >
           --accept 429
           --exclude "^https://zenodo.org/badge/DOI/$"
+          --exclude "^https://doi.org/10.5281/zenodo$"
+          --exclude "^https://doi.org/10.5281/zenodo$"
+          --exclude "^https://zenodo.org/badge/DOI/10.5281/zenodo$"
           --exclude "^https://github.com/GenericMappingTools/pygmt/pull/[0-9]*$"
           --exclude "^https://github.com/GenericMappingTools/pygmt/issues/[0-9]*$"
           --exclude "^https://www.generic-mapping-tools.org/_static/gmt-logo.png/$"
@@ -40,6 +43,7 @@ jobs:
           --exclude "^git"
           --exclude "^file://"
           --exclude "^https://docs.generic-mapping-tools.org/latest/%s$"
+          --exclude "https://hackmd.io/@pygmt"
           --verbose
           "repository/**/*.rst"
           "repository/**/*.md"