✨ Add support for injecting request header value into ban HTML template (#296)

* Add parameter to specify Request header value to inject in HTML template

* Add documentation for specifying request header value

* Fix example in docs for CustomHeader

* Update parameter name to traceCustomHeader

* Ensure naming is consitent with project

README.md

@@ -497,6 +497,10 @@ make run
   - string
   - default: ""
   - Path where the ban html file is stored (default empty ""=disabled)
+- TraceHeadersCustomName
+  - string
+  - default: ""
+  - Request Header name whose value to inject in ban HTML response (default empty ""=disabled)
 
 ### Configuration
 
@@ -603,6 +607,7 @@ http:
           captchaGracePeriodSeconds: 1800
           captchaHTMLFilePath: /captcha.html
           banHTMLFilePath: /ban.html
+          traceHeadersCustomName: X-Request-ID
           metricsUpdateIntervalSeconds: 600
 ```