[Frontend] Home

[b-g]

• [x] add disclaimer: "#slackviz is not created by, affiliated with, or supported by Slack Technologies, Inc." (Text should be a minimum of 15pt. and a minimum of 80% opacity black or white in color. from https://slack.com/brand-guidelines)
• [x] wrong title, it should be "#slackviz"
• [x] hide "Add to Slack" button in online demo website, otherwise too misleading
• [x] wrong text in footer: slackviz made by moovel lab & moovel dev team
• [x] "fork me on github" banner has old link, update to https://github.com/moovel/slackviz/
• [x] page title prefix has to be dynamic: [name of slack data set] #slackviz