Added DevProjects under JavaScript challenges, ReactJS, and Vue. Removed JavaScript Gekk from JavaScript challenges because there's no link to it and I couldn't find it on Google.Added Arc.dev to job sites. Added Codementor to freelance jobs sites.

DevProjects is a community with free real-world projects in multiple coding languages and tech stacks. The website also includes solutions from other developers and discussion board for all users to participate in.

Arc.dev crawls the web to find every remote job and gives developers a personalized list of jobs they are more likely to land.

Codementor is a platform where developers can join to provide others mentorship or look for freelance jobs.

Author: jenniferfu0811

README.md

@@ -243,10 +243,10 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
   - [Codewars](https://www.codewars.com/)
   - [CodinGame](https://www.codingame.com/)
   - [CodeForces](https://codeforces.com/)
+  - [DevProjects](https://www.codementor.io/projects/javascript) - Free real-world JavaScript projects.
   - [Exercism](https://exercism.io/)
   - [HackerEarth](https://www.hackerearth.com/)
   - [Hackerrank](https://www.hackerrank.com/)
-  - [JavaScript Gekk]()
   - [Leetcode](https://leetcode.com/)
   - [Mintbean](https://mintbean.io/) - Free learnathons instead of just algorithms.
   - [Pramp](https://www.pramp.com/#/)
@@ -348,6 +348,10 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
   - [React from Zero 💵](https://www.newline.co/react-from-zero/)
   - [Road to React 💵](https://www.roadtoreact.com/)
 
+- Projects
+
+  - [Devprojects](https://www.codementor.io/projects/reactjs)
+
 - Podcasts
 
   - [React Round Up](https://devchat.tv/react-round-up)
@@ -440,6 +444,7 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
   - [React Rally](http://www.reactrally.com/)
   - [ReactFest](https://reactfest.uk/)
   - [React Europe](https://www.react-europe.org/)
+
 - Community
   - [React Forum](https://discuss.reactjs.org/)
   - [Reactiflux](https://www.reactiflux.com/)
@@ -469,6 +474,9 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
   - VueSchool - [Learn Vue 💵](https://vueschool.io/)
   - Vuemastery - [Premium Beginner to Advanced Vue Course 💵 ](https://www.vuemastery.com/courses)
 
+- Projects
+  - DevProjects - [Free Vue Projects and Community](https://www.codementor.io/projects/vue)
+
 - Books
 
   - [Fullstack Vue 💵](https://www.fullstack.io/vue/)
@@ -770,6 +778,7 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
 
 - Resume Editing
   - [Grammarly](https://www.grammarly.com/)
+
 - ATS Resources
 
   - [JobScan](https://www.jobscan.co/)
@@ -779,6 +788,7 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
 - Job Sites
 
   - [Angel List](https://angel.co/jobs)
+  - [Arc.dev - Remote Developer Jobs](https://arc.dev/)
   - [Find Remote Jobs](https://frontendremotejobs.com/)
   - [Github Jobs](https://jobs.github.com/)
   - [JavaScript Job](https://javascriptjob.xyz/)
@@ -806,6 +816,7 @@ Be sure to read [How To Contribute](CONTRIBUTING.MD)
 
 - Freelance Jobs Sites
 
+  - [Codementor](https://www.codementor.io/)
   - [Freelancer](https://www.freelancer.com/)
   - [FlexJobs](https://www.flexjobs.com/)
   - [FreelancerMap](https://www.freelancermap.com/)