Fix docs links to point to stable (not latest) (#228)

_data/functions/extras.yml

@@ -1,10 +1,10 @@
 functions:
   - title: Build Parts
     text: Inventree features a build management system to help you track the progress of your builds. Builds consume stock items to make new parts, you can decide to automatically or manually allocate parts from your current inventory.
-    link: https://docs.inventree.org/en/latest/part/part/
+    link: https://docs.inventree.org/en/stable/part/part/
   - title: Report
     text: Generate a wide range of reports using custom templates.
-    link: https://docs.inventree.org/en/latest/report/report/
+    link: https://docs.inventree.org/en/stable/report/report/
   - title: Extend and Customize
     text: InvenTree is designed to be highly extensible. If the core InvenTree functionality does not meet your particular need, InvenTree provides a RESTful API, a native Python library, and a powerful plugin system.
-    link: https://docs.inventree.org/en/latest/api/api/
+    link: https://docs.inventree.org/en/stable/api/api/

_data/functions/general.yml

@@ -5,15 +5,15 @@ text:
 functions:
   - title: Organize Parts
     text: Parts are the fundamental element of any inventory. InvenTree groups parts into structured categories which allow you to arrange parts to meet your particular needs. 
-    link: https://docs.inventree.org/en/latest/part/part/
+    link: https://docs.inventree.org/en/stable/part/part/
   - title: Manage Suppliers
     text: InvenTree allows you to easily create, modify or delete suppliers and supplier items linked to any part in your inventory.
-    link: https://docs.inventree.org/en/latest/order/company/#suppliers
+    link: https://docs.inventree.org/en/stable/order/company/#suppliers
   - title: Instant Stock Knowledge
     text: Instantly view current stock for a certain part, in a particular location, or required for an individual build.
     extend: Stock items are organized in cascading locations and sub-locations, allowing flexible inspection of stock under any location. Stock items can be serialized for tracking of individual items, and test results can be stored against a serialized stock item for the purpose of acceptance testing and commissioning.
-    link: https://docs.inventree.org/en/latest/stock/stock/
+    link: https://docs.inventree.org/en/stable/stock/stock/
   - title: BOM Management
     text: Intelligent <strong>B</strong>ill <strong>o</strong>f <strong>M</strong>aterial management provides a clear understanding of the sub-parts required to make a new part.
     extend: InvenTree allows you to upload simple BOM files in multiple formats, and download a detailed BOM with all the information stored in its database.
-    link: https://docs.inventree.org/en/latest/build/bom/
+    link: https://docs.inventree.org/en/stable/build/bom/