docs: add jagmandan as a contributor for code (#140)

Adds @jagmandan as a contributor for code.

This was requested by bourquep [in this
comment](https://github.com/bourquep/mysa-js-sdk/pull/139#issuecomment-3369095675)

[skip ci]

---------

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>

.all-contributorsrc

@@ -0,0 +1,26 @@
+{
+  "files": [
+    "README.md"
+  ],
+  "imageSize": 100,
+  "commit": false,
+  "commitType": "docs",
+  "commitConvention": "angular",
+  "contributors": [
+    {
+      "login": "jagmandan",
+      "name": "jagmandan",
+      "avatar_url": "https://avatars.githubusercontent.com/u/227265405?v=4",
+      "profile": "https://github.com/jagmandan",
+      "contributions": [
+        "code"
+      ]
+    }
+  ],
+  "contributorsPerLine": 7,
+  "skipCi": true,
+  "repoType": "github",
+  "repoHost": "https://github.com",
+  "projectName": "mysa-js-sdk",
+  "projectOwner": "bourquep"
+}