Link word "Introduction"

[lukecaputo]

Link the word "Introduction" to the section that is being referenced.

[ericdouglas]

@lukecaputo thank you for your PR! 🙏

Can you also do the following things?

• Change the text from Introduction to Introduction to Computer Science

• Bump our Curriculum Version to 1.2.5 here, because you're fixing our file.

• Add a little explanation in our CHANGELOG file, saying what you're doing. More explanation about CHANGELOG files here. The text will be something like this:

  [1.2.5] 2015-10-16
  
  ### Fixed
  - Fix name of the section and add a hyperlink to it.
  

[ericdouglas]

@lukecaputo 👏