Install Minifier by searching 'minifier' in the Packages section of Preferences. You can also install the package via the command line with
apm install minifier.
To minify a file, use the keyboard shortcut
Alt+Shift+M on Windows). You can also minify files on save by checking the corresponding option in Preferences.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.