Support max_files in vscode settings

[DoloMike]

Requesting to support max_files in vscode settings as well. I think this would be beneficial because:

• some large projects do not use solargraph by default and thus do not have a .solargraph.yml (i.e., most contributors use an editor like Rubymine).
• they don't want to add a .solargraph.yml to the project file OR add .solargraph.yml to the .gitignore
• vscode settings are a common method of managing dev tool extensions configurability, as opposed to having a specific .config file for each extension

Some reactions to this answer indicate there is some agreement this should also be manageable from vscode settings (instead of only .solargraph.yml
#54 (comment)

Open question pertaining to max_files but would be applicable to any setting that is supported in both places:

• If max_files has a value in both the project's .solargraph.yml as well as the vscode settings, which should take precedence? My assumption is that .solargraph.yml should always be given preference.

[aspirisen]

Any updates? That would be a useful feature

[gabrielesilinic]

@aspirisen @DoloMike you can solve this by having a global config. it seems like it's working for me.

the only downside is that I don't know how it would behave outside of *nix OSes

look at issue #197