Rework macro_tutorial.rst to teach REPL workflow

[gilch]

This incorporates some of the tricks in the https://github.com/gilch/hissp/wiki/Lissp-tricks-and-idioms page into the macro tutorial. Seemed like the right place for it, more or less.

[codecov[bot]]

Codecov Report

Merging #225 (1449f93) into master (5f99cba) will not change coverage. The diff coverage is n/a.

:exclamation: Current head 1449f93 differs from pull request most recent head ccd3608. Consider uploading reports for the commit ccd3608 to get more accurate results

@@           Coverage Diff           @@
##           master     #225   +/-   ##
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  Coverage   99.71%   99.71%           
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  Files           6        6           
  Lines         714      714           
  Branches      110      110           
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  Hits          712      712           
  Misses          1        1           
  Partials        1        1           

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