Add Unlimited Custom hostPath mounts (#201)

.github/docs/development/unlimited-storage-mounts.md

@@ -0,0 +1,69 @@
+# Unlimited Storage Mounts
+
+We support presenting the user with a "Do it yourself" style list, in which the user can add unlimited paths on the host system to mount.
+It should always be included in any App, to give users the option to customise things however they like.
+
+### Example
+
+```
+  - variable: appExtraVolumeMounts
+    label: "Custom app storage"
+    group: "Storage"
+    schema:
+      type: list
+      default: []
+      items:
+        - variable: volumeMount
+          label: "Custom Storage"
+          schema:
+            type: dict
+            attrs:
+              - variable: enabled
+                label: "Enabled"
+                schema:
+                  type: boolean
+                  default: true
+                  required: true
+                  hidden: true
+                  editable: false
+              - variable: setPermissions
+                label: "Automatic Permissions"
+                description: "Automatically set permissions on install"
+                schema:
+                  type: boolean
+                  default: true
+                  hidden: false
+              - variable: name
+                label: "Mountpoint Name"
+                schema:
+                  type: string
+                  default: ""
+                  required: true
+                  editable: true
+              - variable: emptyDir
+                label: "emptyDir"
+                schema:
+                  type: boolean
+                  default: false
+                  hidden: true
+                  editable: false
+              - variable: mountPath
+                label: "Mount Path"
+                description: "Path to mount inside the pod"
+                schema:
+                  type: path
+                  required: true
+                  default: ""
+                  editable: true
+              - variable: hostPathEnabled
+                label: "host Path Enabled"
+                schema:
+                  type: boolean
+                  default: true
+                  hidden: true
+              - variable: hostPath
+                label: "Host Path"
+                schema:
+                  type: hostpath
+                  required: true
+```

.github/docs/general/storage.md

@@ -33,3 +33,7 @@ Setting permissions automatically means we `chown` the folder and all folder wit
 However, we only do so when installing or updating an app.
 
 These permission get based on the user and group you enter in the App configuration dialog and default to `568` (the SCALE default Apps user).
+
+### Custom Storage
+
+Besides the earlier mentioned storage options, we also provide the option to mount as many host folders as you want. This is limited to hostPath mounts only.