Add Intro.js and simple introduction to Homepage

[TomDijkema]

PR adds the intro.js dependency which allows us to create introductions within the application for users to explain the main functionalities. This commit implements a simple tour of the Homepage.

For text reference: https://docs.google.com/document/d/1dQzSEKhBtUAgvU55OTvsAlhP3nf_rIemjef3eAkOzOs/edit

Adds:

• Intro.js dependency
• Simple introduction guide to Homepage
• Introduction to Search Page
• Introduction to Compare functionality
• Introduction to Specimen Page
• Introduction to Annotations
• Introduction to Machine Annotation Services

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

31.0% Coverage
1.5% Duplication