Update the projects list #1551
Description
Detailed description
As we have already completed these below mentioned projects they should be removed from the List to fix.
https://github.com/TheAlgorithms/C-Plus-Plus/projects/6#card-63413879
https://github.com/TheAlgorithms/C-Plus-Plus/projects/6#card-63413841
https://github.com/TheAlgorithms/C-Plus-Plus/projects/6#card-63413788
Context
To keep our TODO list updated.
Possible implementation
Remove the completed projects from the list.
Additional information
No response