Update README.md

[sainat]

Update Readme link to example.

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[afsalthaj]

@sainat Thanks for this contribution. 👍

[afsalthaj]

@sainat Minor
There are issues in website build issue

39
[error] java.lang.RuntimeException: The README.md file is not up-to-date!
[40](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:41)
[error] Please run `sbt docs/generateReadme` and commit new changes.
[41](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:42)
[error] 	at scala.sys.package$.error(package.scala:30)
[42](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:43)
[error] 	at zio.sbt.WebsitePlugin$.$anonfun$checkReadmeTask$1(WebsitePlugin.scala:392)
[43](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:44)
[error] 	at zio.sbt.WebsitePlugin$.$anonfun$checkReadmeTask$1$adapted(WebsitePlugin.scala:387)
[44](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:45)
[error] 	at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[45](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:46)
[error] 	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[46](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:47)
[error] 	at sbt.std.Transform$$anon$4.work(Transform.scala:68)
[47](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:48)
[error] 	at sbt.Execute.$anonfun$submit$2(Execute.scala:282)
[48](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:49)
[error] 	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
[49](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:50)
[error] 	at sbt.Execute.work(Execute.scala:291)
[50](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:51)
[error] 	at sbt.Execute.$anonfun$submit$1(Execute.scala:282)
[51](https://github.com/zio/zio-constraintless/actions/runs/5069401744/jobs/9328764016?pr=26#step:4:52)
[error]