Fix broken TOC links for italic headings (#1378)

Fixed anchor links in table of contents for headings that use underscores for italic formatting (_request_, _message_, etc.).

Author: tzkz

Readme.md

@@ -37,10 +37,10 @@ This module lets you connect to web services using SOAP. It also provides a serv
   - [Client._lastRequest_ - the property that contains last full soap request for client logging](#clientlastrequest---the-property-that-contains-last-full-soap-request-for-client-logging)
   - [Client.setEndpoint(url) - overwrite the SOAP service endpoint address](#clientsetendpointurl---overwrite-the-soap-service-endpoint-address)
   - [Client Events](#client-events)
-  - [_request_](#_request_)
-  - [_message_](#_message_)
-  - [_soapError_](#_soaperror_)
-  - [_response_](#_response_)
+  - [_request_](#request)
+  - [_message_](#message)
+  - [_soapError_](#soaperror)
+  - [_response_](#response)
 - [WSDL](#wsdl)
 - [WSDL.constructor(wsdl, baseURL, options):](#wsdlconstructorwsdl-baseurl-options)
   - [wsdl.xmlToObject(xml):](#wsdlxmltoobjectxml)