Apply convention to lecture formatting

[Dmitrii Kovanikov]

I propose to invent and follow some convention for this course and format whole course according to this convention. I propose the following:

• Use double star ** for bold.
• Use underscore _ for italics.

1. Keywords should be bold plain text.
   Example: data
2. Packages should be in backticks with link to Hackage.
   Example: lens
3. Functions and operators from libraries should be in italics and in backtics with link to Hackage.
   Example: whenJust
4. Language extensions should be in italics with link to haskell user guide started with -X.
   Example: -XRecordWildCards
5. Compiler options should be bold with monospace.
   Example: -ddump-deriv

[zclimber]

Корчагин

[Dmitrii Kovanikov]

@zclimber 👌 You can start doing this

[Dmitrii Kovanikov]

Resolved in #3