docs(docs): 📝 add missing command docs

docs/api/commands/insert-content-at.md

@@ -1,5 +1,26 @@
 # insertContentAt
+The `insertContentAt` will insert a string of html or a node at a given position or range. If a range is given, the new content will replace the content in the given range with the new content.
 
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+## Parameters
+`position: number | Range`
+
+The position or range the content will be inserted in.
+
+`value: Content`
+
+The content to be inserted. Can be a string of HTML or a node.
+
+`options: Record<string, any>`
+
+* updateSelection: controls if the selection should be moved to the newly inserted content.
+* parseOptions: Passed content is parsed by ProseMirror. To hook into the parsing, you can pass `parseOptions` which are then handled by [ProseMirror](https://prosemirror.net/docs/ref/#model.ParseOptions).
+
+## Usage
+```js
+editor.commands.insertContentAt(12, '<p>Hello world</p>', {
+  updateSelection: true,
+  parseOptions: {
+    preserveWhitespace: 'full',
+  }
+})
+```