help-docs: Move help center documentation to top level directory.

These files are not Jinja2 templates, so there's no reason that they needed
to be inside `templates/zerver`. Moving them to the top level reflects their
importance and also makes it feel nicer to work on editing the help center content, 
without it being unnecessary buried deep in the codebase.

.prettierignore

@@ -1,4 +1,5 @@
 /corporate/tests/stripe_fixtures
+/help/**/*.md
 /locale
 /static/third
 /templates/**/*.md

docs/documentation/helpcenter.md

@@ -26,20 +26,18 @@ from the Internet, and we'd like the documentation to be available in that
 environment.
 
 The source for help center documentation is the Markdown files under
-`templates/zerver/help/` in the
-[main Zulip server repository](https://github.com/zulip/zulip). The file
-`foo.md` is automatically rendered by the `render_markdown_path` function in
-`zerver/templatetags/app_filters.py` when the user accesses a URL of the
-form `/help/foo`; with special cases for `/help/` going to `index.md` and
-`/help/unknown_article` going to `missing.md` (with a 404 response). Images
-are usually linked from `static/images/help/`.
+`help/` in the [main Zulip server repository](https://github.com/zulip/zulip).
+The file `foo.md` is automatically rendered by the `render_markdown_path`
+function in `zerver/templatetags/app_filters.py` when the user accesses a URL
+of the form `/help/foo`; with special cases for `/help/` going to `index.md`
+and `/help/unknown_article` going to `missing.md` (with a 404 response).
+Images are usually linked from `static/images/help/`.
 
 This means that you can contribute to the Zulip help center documentation
 by just adding to or editing the collection of Markdown files under
-`templates/zerver/help`. If you have the Zulip development environment
-set up, you simply need to reload your browser on
-`http://localhost:9991/help/foo` to see the latest version of `foo.md`
-rendered.
+`help/...`. If you have the Zulip development environment set up, you simply
+need to reload your browser on `http://localhost:9991/help/foo` to see the
+latest version of `foo.md` rendered.
 
 This system is designed to make writing and maintaining such documentation
 highly efficient. We link to the docs extensively from the landing pages and
@@ -69,9 +67,8 @@ the current documentation as a resource and guide as you begin.
 - Should the feature you're documenting be added or merged into an
   existing article?
 
-  - If so, you can locate that article in
-    `templates/zerver/help` and start working on updating it with
-    content about the new feature.
+  - If so, you can locate that article in `help/` and start working
+    on updating it with content about the new feature.
 
   - If not, choose an existing article to use as a template for your
     new article and make a list of which articles (or guides) would be
@@ -352,8 +349,7 @@ make use of `fa` as a base class.
 phrases and steps at the location of the macros. Macros help eliminate
 repeated content in our documentation.
 
-The source for macros is the Markdown files under
-`templates/zerver/help/include` in the
+The source for macros is the Markdown files under `help/include` in the
 [main Zulip server repository](https://github.com/zulip/zulip).
 
 - **Administrator only feature** `{!admin-only.md!}`: Notes that the feature

docs/tutorials/new-feature-tutorial.md

@@ -68,7 +68,7 @@ organization in Zulip). The following files are involved in the process:
 
 - `zerver/openapi/zulip.yaml`: OpenAPI definitions for the Zulip REST API.
 - `templates/zerver/api/changelog.md`: documentation listing all changes to the Zulip Server API.
-- `templates/zerver/help/...`: end user facing documentation (Help Center) for the application.
+- `help/...`: end user facing documentation (Help Center) for the application.
 
 ### Adding a field to the database
 
@@ -157,10 +157,10 @@ For detailed information on the kinds of documentation Zulip has, see
 [Documentation](../documentation/overview.md).
 
 **Help center documentation:** You will likely need to at least update,
-extend and link to `/help/` articles that are related to your new
-feature. [Writing help center articles](../documentation/helpcenter.md)
+extend and link to articles in the `help/` directory that are related
+to your new feature. [Writing help center articles](../documentation/helpcenter.md)
 provides more detailed information about writing and editing feature
-`/help/` articles.
+`help/` directory articles.
 
 **API documentation:** A new feature will probably impact the REST API
 documentation as well, which will mean updating `zerver/openapi/zulip.yaml`
@@ -696,10 +696,10 @@ this feature would be to update and/or augment Zulip's existing
 changes and additions.
 
 At the very least, this will involve modifying (or adding) a Markdown
-file documenting the feature to `templates/zerver/help/` in the main
-Zulip server repository, where the source for Zulip's end user
-documentation is stored. Details about writing, editing and testing
-these Markdown files can be found in:
+file documenting the feature in the `help/` directory of the main Zulip
+server repository, where the source for Zulip's end user documentation
+is stored. Details about writing, editing and testing these Markdown
+files can be found in:
 [Writing help center articles](../documentation/helpcenter.md).
 
 Also, new features will often impact Zulip's REST API documentation,