Added readme.md to capture the AutoRest configuration for EventGrid data plane. (#2111)
Added readme.md to capture the AutoRest configuration for EventGrid data plane. (#2111)

* Swagger for Azure Event Grid.

* Added x-ms-examples for all the operations.

* Removed TopicTypes_list.json as the casing doesn't match what's referenced in the Swagger.

* Re-adding TopicTypes_List.json with the correct casing.

* Fixed a set of validation errors in the examples.

* Added x-ms-examples for the 2017-09-15-preview API version of Azure Event Grid.

* Fixed examples to avoid the double forward slash in the scope parameter.

* Support for patching an EventGrid topic (to update tags).

* Updated description in the response of topic patch operation.

* Swagger for the Event Grid data plane.

* Fixed the casing of readOnly field, added x-ms-example.

* Fixed a missing parameter in the example file.

* Added readme.md to capture the AutoRest configuration for EventGrid data plane.

Nking92/azure-rest-api-specs,dashimi16/azure-rest-api-specs,kiwidev/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,yugangw-msft/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,kiwidev/azure-rest-api-specs,deathly809/azure-rest-api-specs,hovsepm/azure-rest-api-specs,amolr/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,solankisamir/azure-rest-api-specs,jobatzil/azure-rest-api-specs,hovsepm/azure-rest-api-specs,hyonholee/azure-rest-api-specs,bganapa/azure-rest-api-specs,henry416/azure-rest-api-specs,johanste/azure-rest-api-specs,vladrai/azure-rest-api-specs,AuxMon/azure-rest-api-specs,solankisamir/azure-rest-api-specs,felixwa/azure-rest-api-specs,hyonholee/azure-rest-api-specs,nathannfan/azure-rest-api-specs,vladrai/azure-rest-api-specs,naveedaz/azure-rest-api-specs,sudhansu88/azure-rest-api-specs,henry416/azure-rest-api-specs,Nking92/azure-rest-api-specs,amarzavery/azure-rest-api-specs,JasonYang-MSFT/azure-rest-api-specs,Nking92/azure-rest-api-specs,AuxMon/azure-rest-api-specs,yaakoviyun/azure-rest-api-specs,shimedh/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,johanste/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,naveedaz/azure-rest-api-specs,amarzavery/azure-rest-api-specs,akshaysngupta/azure-rest-api-specs,olydis/azure-rest-api-specs,deathly809/azure-rest-api-specs,yugangw-msft/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,dmakwana/azure-rest-api-specs,yaakoviyun/azure-rest-api-specs,d3r3kk/azure-rest-api-specs