add reference to common source properties in all sources

website/docs/r/cloudsyslog_source.html.markdown

@@ -28,7 +28,7 @@ resource "sumologic_collector" "collector" {
 
 ## Argument reference
 
-Only the common properties are valid.
+  * [Common Source Properties](https://github.com/terraform-providers/terraform-provider-sumologic/tree/master/website#common-source-properties)
 
 ## Attributes reference
 

website/docs/r/collector.html.markdown

@@ -29,6 +29,10 @@ The following arguments are supported:
   * `timezone` - (Optional) The time zone to use for this collector. The value follows the [tzdata][2] naming convention.
   * `fields` - (Optional) Map containing [key/value pairs][3].
 
+### See also
+  * [Common Source Properties](https://github.com/terraform-providers/terraform-provider-sumologic/tree/master/website#common-source-properties)
+
+## Attributes Reference
 The following attributes are exported:
 
   * `id` - The internal ID of the collector. This can be used to attach sources to the collector.

website/docs/r/http_source.html.markdown

@@ -31,6 +31,10 @@ In addition to the common properties, the following arguments are supported:
 
 - `message_per_request` - (Optional) When set to `true`, will create one log message per HTTP request.
 
+### See also
+  * [Common Source Properties](https://github.com/terraform-providers/terraform-provider-sumologic/tree/master/website#common-source-properties)
+
+## Attributes Reference
 The following attributes are exported:
 
 - `id` - The internal ID of the source.
@@ -43,7 +47,7 @@ HTTP sources can be imported using the collector and source IDs (`collector/sour
 terraform import sumologic_http_source.test 123/456
 ```
 
-+HTTP sources can be imported using the collector name and source name (`collectorName/sourceName`), e.g.:
+HTTP sources can be imported using the collector name and source name (`collectorName/sourceName`), e.g.:
 
 ```hcl
 terraform import sumologic_http_source.test my-test-collector/my-test-source

website/docs/r/polling_source.html.markdown

@@ -116,7 +116,10 @@ In addition to the common properties, the following arguments are supported:
           + `namespace` - Namespace for which you want to define the tag filters. Use  value as `All` to apply the tag filter for all namespaces.
           + `tags` - List of key-value pairs of tag filters. Eg: `["k3=v3"]`
 
+### See also
+  * [Common Source Properties](https://github.com/terraform-providers/terraform-provider-sumologic/tree/master/website#common-source-properties)
 
+## Attributes Reference
 The following attributes are exported:
 
 - `id` - The internal ID of the source.