Make RSS feed path configurable (#1034)

* Make RSS feed path configurable

Fixes #997

Add configuration option for RSS feed path

* Add `rssPath` configuration option in `exampleSite/hugo.yaml` under the `params` section to specify the desired RSS feed path.
* Set the default value of `rssPath` to `/rss.xml`.
* Update `layouts/_default/baseof.html` to include the RSS feed link with the configured `rssPath` value.
* Use the default path `/index.xml` if `rssPath` is not specified.

* Add outputFormats to hugo.yaml

Signed-off-by: Emruz Hossain <hossainemruz@gmail.com>

* Add reference to doc

Signed-off-by: Emruz Hossain <hossainemruz@gmail.com>

---------

Signed-off-by: Emruz Hossain <hossainemruz@gmail.com>

exampleSite/hugo.yaml

@@ -1,4 +1,3 @@
-
 baseURL: http://example.org/
 languageCode: en-us
 title: Example Site
@@ -64,6 +63,12 @@ outputs:
     - RSS
     - JSON
 
+# Configure custom path for RSS feed. Default is "index.xml"
+# Ref: https://gohugo.io/templates/output-formats/
+outputFormats:
+  rss:
+    baseName: rss # default is index
+
 # Enable global emoji support
 enableEmoji: true
 
@@ -300,7 +305,6 @@ params:
     readingTime:
       enable: true
 
-
   # Provide footer configuration.
   footer:
     enable: true