Improve documentation deployment workflow

[kefranabg]

Feature request

Deploy documentation to https://vuepress.vuejs.org/ only when we do a new release. For now, documentation is deployed each time we merge PR on master.

Describe the problem

User try to use feature that has not been release yet.

How should this be implemented in your opinion?

Improve release script with a documentation deployment script and disable documentation auto deployment when master is updated.

Are you willing to work on this yourself?

[meteorlxy]

Another suggestion is to use lerna "independent" mode.

@vuepress/core and @vuepress/theme-default (and plugin pkgs) are decoupled since 1.0, so they are not necessary to (maybe should not to 🤔 ) keep the same version.