Consider normalizing spacing and other code style issues

[jeroenheijmans]

Many PRs seem to include changes to whitespace, probably because VSCode plugins for many folks auto-fix files (based on the given config) when they only update one or two lines. For example in my own recent PR many whitespace changes were silently made by VSCode (with only relevant plugins being TSLint and EditorConfig) based on the configs.

Please consider normalizing all spaces and other syntactic things (e.g. trailing comma's and so forth) to match the configs and linting files in the repo. This should prevent future PRs from attracting too many distracting changes.

[manfredsteyer]

Great idea. Just added prettier.