feat: add config option to disable external link warning

Since it is heavily requested by users, this adds a new config option
to disable the previously introduced external link warning.
Be aware however, that disabling this config option weakens the
security of your HedgeDoc instance and is therefore only recommended
for closed trustworthy user groups.

Signed-off-by: Erik Michelson <github@erik.michelson.eu>

public/docs/release-notes.md

@@ -5,6 +5,7 @@
 ### Enhancements
 
 - Added external link whitelist setting (`externalLinkWhitelist` in config.json or `CMD_EXTERNAL_LINK_WHITELIST`) to skip warning page for certain domains
+- Added external link warning setting (`externalLinkWarning` in config.json or `CMD_EXTERNAL_LINK_WARNING`) to disable the external link warning page entirely
 - Enabled `.webp` for file uploads (for all backends but `imgur`, since it does not support it)
 
 ### Bugfixes

public/js/extra.js

@@ -592,6 +592,9 @@ window.postProcess = postProcess
 
 // rewrite external links to go through the /_link warning page
 export function rewriteExternalLinks (view) {
+  if (window.externalLinkWarning === false) {
+    return
+  }
   const whitelist = window.externalLinkWhitelist || []
   view.find('a[href]').each((index, linkTag) => {
     const anchor = $(linkTag)

public/js/lib/common/constant.ejs

@@ -8,6 +8,7 @@ window.allowedUploadMimeTypes = <%- JSON.stringify(allowedUploadMimeTypes) %>
 
 window.linkifyHeaderStyle = '<%- linkifyHeaderStyle %>'
 
+window.externalLinkWarning = <%- JSON.stringify(externalLinkWarning) %>
 window.externalLinkWhitelist = <%- JSON.stringify(externalLinkWhitelist) %>
 
 window.DROPBOX_APP_KEY = '<%- DROPBOX_APP_KEY %>'