Updated custom examples

docs/examples/javascript/auth/login.md

@@ -1 +1,12 @@
-test
+let sdk = new Appwrite();
+
+sdk
+    .setProject('')
+;
+
+sdk.auth.login(
+    'email@example.com',
+    'password',
+    'http://example.com/success', // required for JS SDK
+    'http://example.com/failure' // required for JS SDK
+); // Will redirect to relevant page depends on the operation result

docs/examples/javascript/auth/oauth.md

@@ -1 +1,11 @@
-test 1
+let sdk = new Appwrite();
+
+sdk
+    .setProject('')
+;
+
+sdk.auth.oauth(
+    'facebook',
+    'http://example.com/success',
+    'http://example.com/failure'
+); // Will redirect to relevant page depends on the operation result

docs/examples/javascript/auth/register.md

@@ -1 +1,13 @@
-test 2
+let sdk = new Appwrite();
+
+sdk
+    .setProject('')
+;
+
+sdk.auth.register(
+    'email@example.com',
+    'password',
+    'http://example.com/confirm',
+    'http://example.com/success', // required for JS SDK
+    'http://example.com/failure' // required for JS SDK
+); // Will redirect to relevant page depends on the operation result