Add .gitpod.yml to make dev env easier

[tnir]

gem install jekyll (regardless use of Bundler) looks very slow, which spoils contributor experience on this repo. With Gitpod and its prebuilds feature, a new contributor would focus on what they want to improve.

• Blocked by Add entries for Bundler to the project .gitignore #317

How to test

1. Prepare your account in Gitpod.io (free use for 25 hours a month for everyone)
2. Access to https://gitpod.io/#github.com/tnir/guides/tree/gitpod to launch your workspace
3. Develop anything as usual
4. Stop the running workspace
5. And restart the workspace
6. Check if jekyll starts properly (sometimes fails if the settings is not perfectly configured on Gitpod)
7. Develop anything as usual again

Resources

• Lifecycle of Gitpod workspace: https://www.gitpod.io/docs/release-notes/2019-02-15/february-2019#lifecycles

Signed-off-by: Takuya Noguchi takninnovationresearch@gmail.com

[deivid-rodriguez]

Gitpod looks cool. I don't understand how #317 blocks this though, can you explain?

[tnir]

I don't understand how #317 blocks this

Gitpod has a feature indicating how many untracked files in the working directory, but more than 3000 untracked files due to
bundle config set path vendor/bundle, which is required to include gems under /workspace/gitpod to keep installed gems between stopping and restarting a workspace (which I understand is a limitation of Gitpod as of writing).

This PR is not directly blocked by #317, but without it developer experience with Gitpod is ugly to me.

[deivid-rodriguez]

I see, makes sense!