Add option to disable the external link checker

Author: WispySparks

README.md

@@ -27,6 +27,7 @@ See below for a [full example](#full-example).
 | `allow_missing_href` | Allow anchors with missing href tags | false |
 | `enforce_https` | Require that links use HTTPS | true |
 | `swap_urls` | JSON-encoded map of URL rewrite rules | (empty) |
+| `disable_external` | Disables the external link checker | false |
 | `ignore_url` | Newline-separated list of URLs to ignore | (empty) |
 | `ignore_url_re` | Newline-separated list of URL regexes to ignore | (empty) |
 | `connect_timeout` | HTTP connection timeout | 30 |

action.yml

@@ -48,6 +48,9 @@ inputs:
   timeout:
     description: HTTP request timeout
     required: false
+  disable_external:
+    description: Disables the external link checker
+    required: false
   ignore_url:
     description: Newline-separated list of URLs to ignore
     required: false

proof-html.rb

@@ -71,6 +71,7 @@ def get_str(name)
     },
     :timeout => get_int("TIMEOUT", 120),
   },
+  :disable_external => get_bool("DISABLE_EXTERNAL", false),
   :ignore_urls => ignore_url,
   :swap_urls => swap_urls,
 }