cargo-make.json: add extend.relative property (#4505)

* cargo-make.json: add extend.relative property

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/schemas/json/cargo-make.json

@@ -28,6 +28,25 @@
           "description": "If true, the external makefile is optional and does not need to exist",
           "type": "boolean",
           "default": true
+        },
+        "relative": {
+          "description": "Where the path is relative to",
+          "oneOf": [
+            {
+              "const": "git",
+              "description": "The nearest (up) .git folder location"
+            },
+            {
+              "const": "crate",
+              "description": "Crate root (based on Cargo.toml file)"
+            },
+            {
+              "const": "workspace",
+              "description": "Workspace root (based on second top Cargo.toml file)"
+            },
+            { "type": "null", "description": "Current Makefile location" }
+          ],
+          "default": null
         }
       }
     },