Update Getting Started Documentation -- Remove kstat-kss-builder

[themarkappleby]

After following the getting started steps in the readme and running kalastatic start I am getting the following error: Unknown arguments: extend-drupal8, namespace (and my start/build fails). I did not attempt to set this up within a Drupal project, is this a requirement?

[RobLoach]

PR up over at #525 to allow disabling the Twig extensions.

I updated the docs a bit to accommodate. kstat-kss-builder is rooted as part of KSTAT now, so we don't need it. I'll tweak the Getting Started docs a bit futher.

[RobLoach]

@themarkappleby We've released a new alpha of Kalastatic. Feel free to try out targeting alpha1 and see if this fixes your issue. Thanks!

[themarkappleby]

Hmm, I just tried it out with 4.0.0-alpha1 and I am still getting the same error (Unknown arguments: extend-drupal8, namespace). I copy and pasted the index.html.pug and kalastatic.yaml contents from the readme. My directory structure looks like this:

project/
  - build/
  - kalastatic.yaml
  - node_modules/
    - ...
  - package.json
  - src/
    - index.html.pug

[thiagodemellobueno]

@RobLoach bump!