Restore changes to CONTRIBUTING.md from PR #6489

Author: TiFu

CONTRIBUTING.md

@@ -85,7 +85,8 @@ For [Vendor Extensions](https://github.com/OAI/OpenAPI-Specification/blob/master
 To add test cases (optional) covering the change in the code generator, please refer to [modules/openapi-generator/src/test/java/org/openapitools/codegen](https://github.com/openapitools/openapi-generator/tree/master/modules/openapi-generator/src/test/java/org/openapitools/codegen)
 
 To test the templates, please perform the following:
-- Update the Petstore sample by running the shell scripts under `bin` folder. For example, run `./bin/generate-samples.sh ./bin/configs/python*` to update the Python PetStore samples under [`samples/`](https://github.com/openapitools/openapi-generator/tree/master/samples/). For Windows users, please install [Git BASH](https://gitforwindows.org/) in order to run the scripts.
+- Update the Petstore sample by running the shell scripts under `bin` and `bin/openapi3` folder. For example, run `./bin/python-petstore.sh` and `./bin/openapi3/python-petstore.sh` to update the Python PetStore API client under [`samples/client/petstore/python`](https://github.com/openapitools/openapi-generator/tree/master/samples/client/petstore/python) and [`samples/openapi3/client/petstore/python`](https://github.com/openapitools/openapi-generator/tree/master/samples/openapi3/client/petstore/python). For Windows, the batch files can be found under `bin\windows` folder. (If you find that there are new files generated or unexpected changes as a result of the update, that's not unusual as the test cases are added to the OpenAPI spec from time to time. If you've questions or concerns, please open a ticket to start a discussion)
+- During development it can be helpful to quickly regenerate the samples without recompiling all of openapi-generator, e.g. when you have only updated the mustache templates. This can be done by passing the `-t` parameter: `./bin/python-petstore.sh -t modules/openapi-generator/src/main/resources/python`.
 - Run the tests in the sample folder using maven `mvn integration-test -rf :<artifactId>`, e.g. open a shell in `samples/client/petstore/python`, run `mvn integration-test -rf :PythonPetstoreClientTests`. The artifactId of the project can be found in the pom.xml file. (some languages may not contain unit testing for Petstore and we're looking for contribution from the community to implement those tests)
 - Finally, git commit the updated samples files: `git commit -a`
   (`git add -A` if added files with new test cases)

docs/contributing.md

@@ -89,7 +89,8 @@ For [Vendor Extensions](https://github.com/OAI/OpenAPI-Specification/blob/master
 To add test cases (optional) covering the change in the code generator, please refer to [modules/openapi-generator/src/test/java/org/openapitools/codegen](https://github.com/openapitools/openapi-generator/tree/master/modules/openapi-generator/src/test/java/org/openapitools/codegen)
 
 To test the templates, please perform the following:
-- Update the Petstore sample by running the shell scripts under `bin` folder. For example, run `./bin/generate-samples.sh ./bin/configs/python*` to update the Python PetStore samples under [`samples/`](https://github.com/openapitools/openapi-generator/tree/master/samples/). For Windows users, please install [Git BASH](https://gitforwindows.org/) in order to run the scripts.
+- Update the Petstore sample by running the shell scripts under `bin` and `bin/openapi3` folder. For example, run `./bin/python-petstore.sh` and `./bin/openapi3/python-petstore.sh` to update the Python PetStore API client under [`samples/client/petstore/python`](https://github.com/openapitools/openapi-generator/tree/master/samples/client/petstore/python) and [`samples/openapi3/client/petstore/python`](https://github.com/openapitools/openapi-generator/tree/master/samples/openapi3/client/petstore/python). For Windows, the batch files can be found under `bin\windows` folder. (If you find that there are new files generated or unexpected changes as a result of the update, that's not unusual as the test cases are added to the OpenAPI spec from time to time. If you've questions or concerns, please open a ticket to start a discussion)
+- During development it can be helpful to quickly regenerate the samples without recompiling all of openapi-generator, e.g. when you have only updated the mustache templates. This can be done by passing the `-t` parameter: `./bin/python-petstore.sh -t modules/openapi-generator/src/main/resources/python`.
 - Run the tests in the sample folder using maven `mvn integration-test -rf :<artifactId>`, e.g. open a shell in `samples/client/petstore/python`, run `mvn integration-test -rf :PythonPetstoreClientTests`. The artifactId of the project can be found in the pom.xml file. (some languages may not contain unit testing for Petstore and we're looking for contribution from the community to implement those tests)
 - Finally, git commit the updated samples files: `git commit -a`
   (`git add -A` if added files with new test cases)