Add 'literate-nav' plugin scheme

docs/schema/plugins/external/literate-nav.json

@@ -0,0 +1,27 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema",
+  "title": "Literate nav plugin",
+  "type": "object",
+  "properties": {
+    "literate-nav": {
+      "markdownDescription": "https://github.com/oprypin/mkdocs-literate-nav",
+      "type": "object",
+      "properties": {
+        "nav_file": {
+          "title": "The name of the file to read to determine the navigation for a particular directory under `docs_dir`",
+          "markdownDescription": "https://oprypin.github.io/mkdocs-literate-nav/reference.html#nav_file",
+          "type": "string",
+          "default": "SUMMARY.md"
+        },
+        "implicit_index": {
+          "title": "If set and a directory has a file named `index.md` or `README.md`, but the literate nav for that directory that never includes it, it will be inserted as the first item of the nav",
+          "markdownDescription": "https://oprypin.github.io/mkdocs-literate-nav/reference.html#implicit_index",
+          "type": "boolean",
+          "default": false
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "additionalProperties": false
+}