added snap-in-surface docs

fern/docs/pages/references/snap-in-surfaces.mdx

@@ -0,0 +1,23 @@
+This section explores how to create a custom user interface using snap-kit and DevRev.
+
+## Defining the surfaces with the API 
+
+TODO
+API definition and explanation how to add an snap-in to a given surface.
+Explanation of how to enable handling of snapkit-action.execute to return diffrent snapkits depending on the context from where the call has been made (issue id for example)
+
+## Accessing created snap-in surfaces
+
+After installing and enabling a snap-in on issues, it can be accessed through a button that appears on issue details. Note that the button only appears if there's at least one snap-in defined as accessible from issues.
+
+![snap-in-surface-button](https://github.com/starlightknown/blender-portfolio/assets/74637789/78a6d46a-13bd-4310-964e-00492e4ef86d)
+
+Clicking on the snap-in button shows a list of all possible snap-in after which clicking on one of the options opens an modal 
+
+### Display modal
+
+By default the snapkit defined in the main snap-in is shown, but in the case `snapkit-action.execute` support for showing diffrent snapkits depending on the context was added a call is made and the custom snapkit is shown instead.
+
+![snap-in-surface-modal](https://github.com/starlightknown/blender-portfolio/assets/74637789/65274552-6317-4af9-b04b-c03a651eb412)
+
+

fern/versions/public.yml

@@ -147,6 +147,8 @@ navigation:
             path: ../docs/pages/references/hooks.mdx
           - page: Snapkit
             path: ../docs/pages/references/snapkit.mdx
+          - page: Snap-in surfaces
+            path: ../docs/pages/references/snap-in-surfaces.mdx
           - page: Snap-in resources
             slug: snap-in-resources
             path: ../docs/pages/references/snap-in-resources.mdx