Docs: Consistent example headings & text pt3 (refs #5446) (#6492)
Docs: Consistent example headings & text pt3 (refs #5446) (#6492)

* Docs: Consistent example headings & text pt3 #5446

Just a single doc in this batch due to variance in changes:

Headings were already present, however they were
over-complicated; I separated out the old (ES3/5) feature
from the heading and put it in a block quote to distinguish
it from the new (Reflect API) feature.

As per previous batches, ensured text above examples is
consistent as per #5446

This PR does not attempt to address issues other than
those stated above; such issues will be dealt with on
subsequent sweeps of the docs detailed in #6444.

* Docs: space around fenced code

* Docs: Remove blockquotes (refs #6492)

AcceptableIce/eslint,eslint/eslint,DavidAnson/eslint,Moeriki/eslint,platinumazure/eslint,AcceptableIce/eslint,Aladdin-ADD/eslint,martijndeh/eslint,kentcdodds/eslint,ABaldwinHunter/eslint,pvamshi/eslint,scriptdaemon/eslint,mzgol/eslint,Aladdin-ADD/eslint,platinumazure/eslint,ABaldwinHunter/eslint,BenoitZugmeyer/eslint,eslint/eslint,kentcdodds/eslint,mzgol/eslint,ljharb/eslint,vitorbal/eslint,menelaos/eslint-solarized,onurtemizkan/eslint,brgibson/eslint,vitorbal/eslint,brgibson/eslint,Trott/eslint,Moeriki/eslint,jrencz/eslint,gabro/eslint,scriptdaemon/eslint,DavidAnson/eslint,martijndeh/eslint,Trott/eslint,jrencz/eslint,menelaos/eslint-solarized,SimenB/eslint,SimenB/eslint,gabro/eslint,Gillespie59/eslint,Gillespie59/eslint,whitneyit/eslint,ljharb/eslint,pvamshi/eslint,BenoitZugmeyer/eslint,onurtemizkan/eslint,whitneyit/eslint