Sublime Text Default HTML comments - twig

Question

It looks like when I installed a PHP Twig syntax package it altered the default HTML comment output from <!-- … --> to {# … #}
So, I removed the package, but it still outputs the comment as Twig when I press the keyboard shortcut.
BTW, the key mapping is correct (super+alt+forward_slash), but it's returning a Twig formatted comment instead of an HTML comment.
How do I get back to <!-- … -->
???

Answer 1

It seems as if there is something a little hinky with either your installation of the package or it's removal, so some investigation will be needed in order to resolve the problem.
For background, the settings information for what character or characters to use for comments (either single line or block) is provided by a file of type tmPreferences (not tmLanguage as is erroneously described in the tutorial that you linked to in the comments on your question).
The name of the file and the package that it is contained in don't matter (except in that they control the order the files are loaded in), only the content of said file.
The package that you installed (PHP-Twig) includes the file Preferences/Comments.tmPreferences to set the comments to use in twig files. As seen in this commit, the file contains this subset of information that controls comments:
<key>scope</key>
<string>text.html.twig</string>
<key>settings</key>
<dict>
<key>shellVariables</key>
<array>
<dict>
<key>name</key>
<string>TM_COMMENT_START</string>
<key>value</key>
<string>{# </string>
</dict>
<dict>
<key>name</key>
<string>TM_COMMENT_END</string>
<key>value</key>
<string> #}</string>
</dict>
</array>
</dict>
This says that for the syntax scope text.html.twig, the shellVariables settings TM_COMMENT_START and TM_COMMENT_STOP are {# and #} respectively. With this in place, any time the scope at the cursor location matches text.html.twig and you trigger the comment command, these are used to wrap the commented section.
With that said, these comment characters should only apply when the scope matches text.html.twig. The scope used in regular HTML files is text.html.basic (assuming you're using the HTML package that ships with Sublime), and so it should not match and the comments should not be used there.
You can check the scope of any particular location by using Tools > Developer > Show Scope Name... from the menu or the key binding visible for it from the menu in order to verify.
If you were seeing these comments appear in regular HTML files as well, you may have set Sublime to use the twig syntax for HTML files either intentionally or accidentally, which you can check by checking the right side of the status bar which tells you the syntax that's in use.
On the other hand the problem should also have resolved itself when you removed the package, since that would have removed the tmPreferences file that's providing the comment settings.
I would perform the following checks to see if they have any effect:
Open up an HTML file and verify that the status bar says that it's a file of type HTML and not HTML (Twig) or something else. If it's something else, use View > Syntax > Open all with current syntax as from the menu to set it back to HTML and see if that fixes the problem for HTML files.
Add "PHP-Twig" to the ignored_packages setting in your preferences and see if that helps.
If the file type is wrong or adding PHP-Twig to the list of ignored packages solves the problem, then the package is still installed. If you used Package Control to install it, try removing it again and see if that has any effect (check the Sublime console for errors as well in case the removal is failing for some reason).
You could also select Preferences > Browse Packages from the menu to open the location where Sublime stores all of your unpacked packages. PHP-Twig should not install unpacked, so if you see a folder by that name delete it or move it away from that folder so Sublime can't see it.
From that Packages folder, go up one level in the file hierarchy and then go into the Installed packages folder; this is where user packages that are installed as sublime-package files (most packages fall into this category) are stored and verify that there is not a PHP-Twig.sublime-package file. As above, if you see a file by that name, move it away from that folder so Sublime can't see it and see if that helps.
Failing that the only obvious things that come to mind would be stray tmPreferences files somewhere. The most likely location for such a thing would be one of the folders in the Packages folder (the first one we checked above).