changed color for strings and classes

[KavenArango]

I changed the string and method/class color to something easier to see.

[kcmr]

Hi @KavenArango

The change is OK for me (except for the function color that looks too dark), however it is too small to include it in a new release and it is a personal preference. I can approve your PR but I won't release a new version for now.

Meanwhile, you can customize the theme using preferences:

"editor.tokenColorCustomizations": {
  "[Electron]": {
    "textMateRules": [
      {
        "scope": "string",
        "settings": {
          "foreground": "#35d195"
        }
      },
      {
        "scope": "entity.name.function, meta.require, support.function.any-method",
        "settings": {
          "foreground": "#239683"
        }
      },
      {
        "scope": "meta.class",
        "settings": {
          "foreground": "#91a33e"
        }
      },
      {
        "scope": "keyword.other.special-method",
        "settings": {
          "foreground": "#239683"
        }
      }
    ]
  }
}