linux_web_app documentation fixes (#24202)

* Update application_gateway.html.markdown

Fix typo "A `probe` block support the following" -> "A `probe` block supports the following"

* Update windows_web_app.html.markdown

correct sticky_settings "exports" -> "supports" the following

* Update linux_web_app.html.markdown

Change "Arguments Reference" to "Argument Reference" to match standard

Correct "sticky_settings exports" to "supports" in Argument Reference section.

website/docs/r/linux_web_app.html.markdown

@@ -41,7 +41,7 @@ resource "azurerm_linux_web_app" "example" {
 
 ```
 
-## Arguments Reference
+## Argument Reference
 
 The following arguments are supported:
 
@@ -764,7 +764,7 @@ A `status_code` block supports the following:
 
 ---
 
-A `sticky_settings` block exports the following:
+A `sticky_settings` block supports the following:
 
 * `app_setting_names` - (Optional) A list of `app_setting` names that the Linux Web App will not swap between Slots when a swap operation is triggered.