docs: fix typos and clarify statement (#29626)
docs: fix typos and clarify statement (#29626)

For clarity, change the sentence: 
"*D3** does not introduce a new visual representation."
to read as above. 
Change the closing sentence from:
" So, with just some basic knowledge of latest HTML5 features such as SVG, Canvas you can dive into a world where library like **D3.js** bring data to life!" to what is written above. 
Fix typo: Italic item had extra '*' in markdown syntax, this was removed:  *D3** changed to *D3*.
BhaveshSGupta/FreeCodeCamp,jonathanihm/freeCodeCamp,FreeCodeCamp/FreeCodeCamp,raisedadead/FreeCodeCamp,raisedadead/FreeCodeCamp,jonathanihm/freeCodeCamp,FreeCodeCamp/FreeCodeCamp,BhaveshSGupta/FreeCodeCamp,BhaveshSGupta/FreeCodeCamp