docs: Update link to Handlebars Block Helpers.

This also removes an unused link.

docs/overview/architecture-overview.md

@@ -116,7 +116,7 @@ For more details on the frontend, see our documentation on
 [the static asset pipeline](../subsystems/html-css.html#static-asset-pipeline).
 
 [Jinja2]: http://jinja.pocoo.org/
-[Handlebars]: http://handlebarsjs.com/
+[Handlebars]: https://handlebarsjs.com/
 
 ### nginx
 

docs/overview/directory-structure.md

@@ -48,7 +48,7 @@ templating systems.
 * `templates/zerver/` For [Jinja2](http://jinja.pocoo.org/) templates
   for the backend (for zerver app; logged-in content is in `templates/zerver/app`).
 
-* `static/templates/` [Handlebars](http://handlebarsjs.com/) templates for the frontend.
+* `static/templates/` [Handlebars](https://handlebarsjs.com/) templates for the frontend.
 
 ----------------------------------------
 

docs/subsystems/html-css.md

@@ -265,11 +265,10 @@ Read more about these module systems here:
 * [CommonJS](https://nodejs.org/api/modules.html#modules_modules)
 
 [Jinja2]: http://jinja.pocoo.org/
-[Handlebars]: http://handlebarsjs.com/
+[Handlebars]: https://handlebarsjs.com/
 [trans]: http://jinja.pocoo.org/docs/dev/templates/#i18n
 [i18next]: https://www.i18next.com
 [official]: https://www.i18next.com/plurals.html
-[helpers]: http://handlebarsjs.com/block_helpers.html
 [jconditionals]: http://jinja.pocoo.org/docs/2.9/templates/#list-of-control-structures
-[hconditionals]: http://handlebarsjs.com/block_helpers.html
+[hconditionals]: https://handlebarsjs.com/guide/#block_helpers.html
 [translation]: ../translating/translating.md

docs/testing/linters.md

@@ -197,7 +197,7 @@ option of puppet.
 Zulip uses two HTML templating systems:
 
 - [Django templates](https://docs.djangoproject.com/en/1.10/topics/templates/)
-- [handlebars](http://handlebarsjs.com/)
+- [handlebars](https://handlebarsjs.com/)
 
 Zulip has an internal tool that validates both types of templates for
 correct indentation and matching tags.  You can find the code here:

docs/translating/internationalization.md

@@ -296,7 +296,7 @@ organizations from the command line.
 
 
 [Jinja2]: http://jinja.pocoo.org/
-[Handlebars]: http://handlebarsjs.com/
+[Handlebars]: https://handlebarsjs.com/
 [trans]: http://jinja.pocoo.org/docs/dev/templates/#i18n
 [i18next]: https://www.i18next.com
 [official]: https://www.i18next.com/plurals.html