chore: don't bring source files to end-user

[hyperz111]

Remove source files to end-user package. I see if this is reducing ±20% of package size.

[fb55]

Source files are needed for source maps to work. Users will see errors if source files aren't present.

[hyperz111]

Source files are needed for source maps to work. Users will see errors if source files aren't present.

But users don't use the source files on src. Only distribution files on dist directory.