Mod custom assertion examples

[nowsprinting]

• Replace custom Comparer and Constraint example from test-helper package
• Mod README.md

[github-actions]

Code Metrics Report

	master (96d50f1)	#16 (84bb3e2)	+/-
Coverage	38.3%	37.1%	-1.2%
Code to Test Ratio	1:44.2	1:44.2	+0.0
Test Execution Time	7m51s	5m15s	-2m36s

Details

  |                     | master (96d50f1) | #16 (84bb3e2) |  +/-   |
  |---------------------|------------------|---------------|--------|
- | Coverage            |            38.3% |         37.1% |  -1.2% |
  |   Files             |               30 |            30 |      0 |
  |   Lines             |              507 |           507 |      0 |
- |   Covered           |              194 |           188 |     -6 |
+ | Code to Test Ratio  |           1:44.2 |        1:44.2 |   +0.0 |
  |   Code              |             1334 |          1334 |      0 |
+ |   Test              |            58897 |         58910 |    +13 |
+ | Test Execution Time |            7m51s |         5m15s | -2m36s |

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Reported by octocov