Update function_app.html.markdown (#4073)

* Update function_app.html.markdown

I have run into hours of headaches with Azure in particular -- unless some default app settings are specified / seeded within my terraform code. Please include note specified under app settings (and/or something similar). We deploy with Azure DevOps release pipeline, and without these defaults, we cannot successfully deploy to a terraformed function app.

* Update function_app.html.markdown

website/docs/r/function_app.html.markdown

@@ -99,6 +99,10 @@ The following arguments are supported:
 
 * `app_settings` - (Optional) A key-value pair of App Settings.
 
+~> **Note:** When integrating a `CI/CD pipeline` and expecting to run from a deployed package in `Azure` you must seed your `app settings` as part of terraform code for function app to be successfully deployed. `Important Default key pairs`: (`"WEBSITE_RUN_FROM_PACKAGE" = ""`, `"FUNCTIONS_WORKER_RUNTIME" = "node"` (or python, etc), `"WEBSITE_NODE_DEFAULT_VERSION" = "10.14.1"`, `"APPINSIGHTS_INSTRUMENTATIONKEY" = ""`).
+
+~> **Note:**  When using an App Service Plan in the `Free` or `Shared` Tiers `use_32_bit_worker_process` must be set to `true`.
+
 * `auth_settings` - (Optional) A `auth_settings` block as defined below.
 
 * `enable_builtin_logging` - (Optional) Should the built-in logging of this Function App be enabled? Defaults to `true`.