[WIP] authentication

Author: adespawn

docs/src/authentication.md

@@ -0,0 +1,22 @@
+# Authentication
+
+The driver supports only authentication through plain text:
+
+In case you are using plain-text authentication on the server, you can set the `credentials` when creating the
+`Client` instance, or provide the instance of `PlainTextAuthProvider` through `authProvider` client option.
+
+```javascript
+const scylla = require("scylladb-driver-alpha");
+const client = new scylla.Client({
+  contactPoints,
+  credentials: { username: 'my_username', password: 'very_secure_password!'}
+});
+```
+
+```javascript
+const scylla = require("scylladb-driver-alpha");
+const client = new scylla.Client({
+  contactPoints,
+  authProvider: new scylla.auth.PlainTextAuthProvider('my_username', 'very_secure_password!')
+});
+```