fixed punctuation issues and modified text in wagtail documentation. (#8262)

docs/advanced_topics/documents/title_generation_on_upload.md

@@ -22,7 +22,7 @@ To modify the generated `Document` title, access and update `event.detail.data.t
 
 For single document uploads, the custom event will only run if the title does not already have a value so that we do not overwrite whatever the user has typed.
 
-You can prevent the default behaviour by calling `event.preventDefault()`. For the single upload page or modals, this will not pre-fill any value into the title. For multiple upload, this will avoid any title submission and use the filename title only (with file extension) as a title is required to save the document.
+You can prevent the default behaviour by calling `event.preventDefault()`. For the single upload page or modals, this will not pre-fill any value into the title. For multiple uploads, this will avoid any title submission and use the filename title only (with file extension) as a title is required to save the document.
 
 The event will 'bubble' up so that you can simply add a global `document` listener to capture all of these events, or you can scope your listener or handler logic as needed to ensure you only adjust titles in some specific scenarios.
 

docs/topics/pages.md

@@ -372,7 +372,7 @@ The first argument must match the value of the `related_name` attribute of the `
 
 Wagtail uses Django's [multi-table inheritance](https://docs.djangoproject.com/en/3.1/topics/db/models/#multi-table-inheritance) feature to allow multiple page models to be used in the same tree.
 
-Each page is added to both Wagtail's builtin {class}`~wagtail.models.Page` model as well as its user-defined model (such as the `BlogPage` model created earlier).
+Each page is added to both Wagtail's built-in {class}`~wagtail.models.Page` model as well as its user-defined model (such as the `BlogPage` model created earlier).
 
 Pages can exist in Python code in two forms, an instance of `Page` or an instance of the page model.
 

docs/topics/writing_templates.rst

@@ -218,7 +218,7 @@ Used to load anything from your static files directory. Use of this tag avoids r
     ...
     <img src="{% static "name_of_app/myimage.jpg" %}" alt="My image"/>
 
-Notice that the full path name is not required and the path snippet you enter only need begin with the parent app's directory name.
+Notice that the full path is not required - the path given here is relative to the app's ``static`` directory. To avoid clashes with static files from other apps (including Wagtail itself), it's recommended to place static files in a subdirectory of ``static`` with the same name as the app.
 
 
 Multi-site support