move old JLine 3 example to wiki

[thetoothpick]

Update JLine 3 readme to only show most recent example, and link to old examples on the wiki.

fixes #1098.

[codecov-commenter]

Codecov Report

Merging #1117 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1117   +/-   ##
=========================================
  Coverage     94.36%   94.36%           
  Complexity      448      448           
=========================================
  Files             2        2           
  Lines          6633     6633           
  Branches       1782     1782           
=========================================
  Hits           6259     6259           
  Misses           99       99           
  Partials        275      275           

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[thetoothpick]

In our codebase, I moved the picocli command object itself into a separate class, leaving only the JLine3 main method. Doing this here would clean up the example code and probably make it easier for someone else to incorporate into their project - thoughts @remkop ?

[remkop]

Thank you!
Working on some other commitments now, I will take a detailed look soon.

[remkop]

Merged into master. (Sorry it took a while.)
Thank you for the contribution!