Steps to add VS solution to Visual Studio Team Services

Steps to add an existing Visual Studio solution to a repository on Visual Studio Team Services (or Team Foundation Server).

1. Install Git on your PC first.
2. Create a project with Git as version control on your Visual Studio Team Services website.
3. Get the URL of the new project after it is created,
   i.e., https://developer2201.visualstudio.com/WebApp1/_git/WebApp1
4. Assuming your Visual Studio solution folder is C:\Dev\VS2017_Eval\WebApp1...
5. Open command line console. Go to "C:\Dev\VS2017_Eval\WebApp1".
6. Run command: git init
7. Run command:
   git remote add origin https://developer2201.visualstudio.com/WebApp1/_git/WebApp1
8. add ".gitignore" file to the folder. You can download it from github at
   https://github.com/github/gitignore/blob/master/VisualStudio.gitignore. 
9. Run command: git add .gitignore
10. Run command: git commit -m ".gitignore file added"
11. Run command: git add *
12. Run command: git commit -m "Initial source codes"
13. Run command: git push -u origin --all

Step 13 can be done in Visual Studio by using Sync and Push in outgoing commit in Visual Studio, too.