Update NNCLR model example in docs

[MalteEbner]

Description

Changes

• Adds more info to the NNCLR model example here: https://docs.lightly.ai/self-supervised-learning/examples/nnclr.html
• Structure is similar to the one for SimCLR, see Update SimCLR model model example #1782
• Example of the updated version is attached
  

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.24%. Comparing base (7f84a56) to head (a6e6a24).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1790   +/-   ##
=======================================
  Coverage   85.24%   85.24%           
=======================================
  Files         163      163           
  Lines        6833     6833           
=======================================
  Hits         5825     5825           
  Misses       1008     1008           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[guarin]

LGTM except for the list rendering (see comment).