Protect mustache/hogan blocks from being altered by prettier => prevent runtime errors

[adrienjoly]

In #296, we found that, while reformatting a HTML template that contained mustache/hogan blocks embedded in JavaScript code, prettier broke those blocks, causing bugs in the UI.

For instance, resulting to the following invalid template:

{ { # shouldDisplay } }
window.alert('coucou');
{ { / shouldDisplay } } 

The best workaround I found so far was to add multiline JS comments around those templating elements.

For instance:

/*{{#shouldDisplay}}*/
window.alert('coucou');
/*{{/shouldDisplay}}*/

=> This workaround prevents prettier from trying to re-format these templating elements.

Let's prevent these kinds of bugs from happening again by protecting these blocks.

Note: we're open for alternative ideas on how to fix this reliably and sustainbly.

[adrienjoly]

Spotted { {#hasMore } } in app/templates/userProfileV2.html, after letting vscode reformat the js/jquery section of the file, on save, while developing PR #346: