Add git commit info to website

[stared]

The idea is to add build info (hash, date, link to the git commit) on the website. One of this to:

• make it clear which version we run
• give the sense of continuous development
• give message that it is open source and people are invited to contribute

Some potentially useful blog posts and packges:

• http://www.marcusoft.net/2015/08/npm-scripting-git-version-and-deploy.html
• https://stackoverflow.com/questions/48391897/add-git-information-to-create-react-app
• https://medium.com/@masnun/node-js-getting-current-git-commit-information-on-an-app-753a1835c57c
• https://www.npmjs.com/package/git-repo-info
• https://www.npmjs.com/package/git-revision-webpack-plugin

[stared]

Fixed a long time ago.