Added documentation for template/variant parts

docs/part/template.md

@@ -5,5 +5,41 @@ layout: page
 
 ## Part Templates
 
-!!! missing "TODO"
-	Parameter documentation to be written
+There are various purposes for using Part Templates, among them:
+
+* Template parts can hold information that can be re-used across "Variants", a template part could be useful for creating a base variant of an assembly which can be derived from, with BoM changes for instance.
+* Variants can be used as "manufacturing variants" where the variant dictates a particular configuration which a customer can order: a variant might determine the particular options that come with a part, like harnesses, enclosure, color, specs, etc.
+
+"Variants" parts will reference the "Template" part therefore explicitly creating and showing direct relationship.
+They also allow you to do special things like:
+
+* **Serial Numbers**  
+Parts that are linked in a template / variant relationship must have unique serial numbers (e.g. if you have a template part Widget, and two variants Widget-01 and Widget-02 then any assigned serial numbers must be unique across all these variants).
+* **Stock Reporting**  
+The "stock" for a template part includes stock for all variants under that part.
+* **Logical Grouping**  
+The template / variant relationship is subtly different to the category / part relationship.
+
+### Enable Template Part
+
+Any part can be set as "Template" part. To do so:
+
+1. navigate to a specific part detail page
+0. click on the "Details" tab
+0. locate the part options on the right-hand side
+0. toggle the `Template` option so it shows green / slider to the right:
+{% with id="enable_template_part", url="part/enable_template_part.png", description="Enable Template Part Option" %}
+{% include 'img.html' %}
+{% endwith %}
+
+### Create Variant
+
+When a part's [*Template option*](#enable-template-part) is turned-on, "Variants" of this part can be created.
+
+To create a variant, navigate to a specific part detail page, click on the "Variants" tab then click on the "New Variant" button.
+The `Create Variant` form will be displayed:
+{% with id="create_part_variant", url="part/create_part_variant.png", description="Create Part Variant Form" %}
+{% include 'img.html' %}
+{% endwith %}
+
+Fill-out the form then click on the "Submit" button to create the variant.