GIthub Login (#578)

* Add files via upload

* Create linode-setup.md

* Create cloudflare-setup.md

* Update cloudflare-setup.md

* Delete 4-linode.png

* Delete 3-linode.png

* Add files via upload

* Add files via upload

* Update cloudflare-setup.md

* Update linode-setup.md

* Rename cloudflare-setup.md to cloudflare.md

* Rename linode-setup.md to linode.md

* Update mkdocs.yml

* Update cloudflare.md

* Update linode.md

* Update README.md

* Update README.md

* Update linode.md

sentence in Italian

* v1

The frontend has been completed, along with the .env variables.

However, there is an issue of infinite loading thereafter.

* Fix email and remove deprecated GitHub passport

* Update user_auth_system.md

add How to Set Up a Github Authentication

* Update .env.example

Improved the comment above the GitHub client ID and secret.

* Update user_auth_system.md

* Update package.json

* Remove unnecessary passport GitHub package

* fixed conflicts

 fixed conflicts between Berry-13:main and danny-avila:main

in api/server/index.js 45:54

* Delete e -i HEAD~2

api/strategies/githubStrategy.js

@@ -0,0 +1,47 @@
+const passport = require('passport');
+const { Strategy: GitHubStrategy } = require('passport-github2');
+const config = require('../../config/loader');
+const domains = config.domains;
+
+const User = require('../models/User');
+
+// GitHub strategy
+const githubLogin = new GitHubStrategy(
+  {
+    clientID: process.env.GITHUB_CLIENT_ID,
+    clientSecret: process.env.GITHUB_CLIENT_SECRET,
+    callbackURL: `${domains.server}${process.env.GITHUB_CALLBACK_URL}`,
+    proxy: false,
+    scope: ['user:email'] // Request email scope
+  },
+  async (accessToken, refreshToken, profile, cb) => {
+    try {
+      let email;
+      if (profile.emails && profile.emails.length > 0) {
+        email = profile.emails[0].value;
+      }
+
+      const oldUser = await User.findOne({ email });
+      if (oldUser) {
+        return cb(null, oldUser);
+      }
+
+      const newUser = await new User({
+        provider: 'github',
+        githubId: profile.id,
+        username: profile.username,
+        email,
+        emailVerified: profile.emails[0].verified,
+        name: profile.displayName,
+        avatar: profile.photos[0].value        
+      }).save();
+
+      cb(null, newUser);
+    } catch (err) {
+      console.error(err);
+      cb(err);
+    }
+  }
+);
+
+passport.use(githubLogin);