Update Custom-ROS2-Interfaces.rst

[followthwhiterabbit]

I have changed the executable file's name inside add_executable in CmakeLists.txt file. Because the files were from the previous sum for 2 arguments from the console but the files we updated were designed for three items.

[clalancette]

I see what you are saying about this being a bit confusing, but if we are going to do this we are going to have to add additional text as well. In particular, we are going to have to tell the user to rename their files from add_two_ints_server.cpp and add_two_ints_client.cpp (what they created in previous tutorials) to add_three_ints_server.cpp and add_three_ints_client.cpp, respectively.

I'm honestly not sure that is worth it. It is going to add more text, for a minor increase in understanding.

[followthwhiterabbit]

It may not be worth it, yes, you're right, I am following the tutorials and had a build error problem, most of the people who follow the documentation should have found the solution already, I am just being meticulous

[fujitatomoya]

most of the people who follow the documentation should have found the solution already

maybe.

but as tutorial, this PR fixes right, and adding the sentence like you need to change the file names ... seems to be the right thing here as @clalancette suggested.

[clalancette]

I'm going to close this one out for now, since I don't think we are going to merge this as-is. Thanks for the contribution, though.