Improvements to docs page build

[wende]

Continuation of #210 due to problems with the website:

• Page is too wide
• Top menu isn't center aligned with the rest of the page
• Elchemy-core changes that shouldn't be there

CC @baransu

[wende]

@baransu bump

[baransu]

I haven't had time to look into it and I won't have time until next weekend unfortunately. 😞

[baransu]

I'm not 100% sure how git submodules work but I've checkout elchemy-core to current commit that we're using on master branch of elchemy.

[wende]

@baransu after updating the branch to master it should be desired behaviour then (no changes to core)

[wende]

The main cause of reverting this PR was the page width which causes horizontal scroll and was significantly impairing the experience on mobile devices

[baransu]

The width is fixed.

What do you thing about adding make build-page to release rule so docs page will be always up to date with the latest release?

[wende]

@baransu sounds good. I would add it right after make release in ./bump.sh then