feat(#317): add createResource method

.changeset/ten-students-study.md

@@ -0,0 +1,5 @@
+---
+"druxt": minor
+---
+
+Added createResource method to DruxtClient

packages/druxt/src/client.js

@@ -136,6 +136,37 @@ class DruxtClient {
     }
   }
 
+  /**
+   * Create a JSON:API resource.
+   *
+   * @param {object} resource - The JSON:API resource object
+   *
+   * @returns {object} The response data
+   */
+  async createResource(resource) {
+    const { href } = await this.getIndex(resource.type)
+    if (!href) {
+      return false
+    }
+
+    let response
+    try {
+      response = await this.axios.post(
+        href,
+        { data: resource },
+        {
+          headers: {
+            'Content-Type': 'application/vnd.api+json'
+          }
+        }
+      )
+    } catch (err) {
+      response = (err.response || {}).data || err.message
+    }
+
+    return response
+  }
+
   /**
    * Get a collection of resources from the JSON:API server.
    *