Lab1, 2 and 3 changes

[sdutta9]

Proposed changes

lab1, lab2 and lab3 content added.

[apcurrier]

I made a couple of suggestions, but everything I reviewed looked technically correct.

We should standardize the labs on how we refer to Feature e.g lowercase vs. Camel Case. We (all of us) tend to use both Nginx and NGINX without distinction.

Also, it turns out only "old people" use double spaces after a sentence because they learned to type on typewriters or word processors and not computers. The standard accepted format is one space after a sentence on anything destined to be printed or online. I do this a lot too... it's easy enough to search for the double space and replace it.

Other than these small suggestions, I think we are good to publish these three labs!