sumologicexporter: extract source templates as another README section

Signed-off-by: Dominik Rosiek <[email protected]>

Author: Dominik Rosiek

exporter/sumologicexporter/README.md

@@ -12,14 +12,14 @@ Empty string means no compression
 - `log_format` (optional) (logs only): Format to use when sending logs to Sumo. (default `json`) (possible values: `json`, `text`)
 - `metric_format` (optional) (metrics only): Format of the metrics to be sent (default is `prometheus`) (possible values: `carbon2`, `graphite`, `prometheus`).
 - `graphite_template` (default=`%{_metric_}`) (optional) (metrics only): Template for Graphite format.
-Placeholders `%{attr_name}` will be replaced with attribute value for `attr_name`. `%{_metric_}` is going to be replaced with metric name.
+[Source templates](#source-templates) are going to be applied.
 Applied only if `metric_format` is set to `graphite`.
 - `source_category` (optional): Desired source category. Useful if you want to override the source category configured for the source.
-Placeholders `%{attr_name}` will be replaced with attribute value for `attr_name`.
+[Source templates](#source-templates) are going to be applied.
 - `source_name` (optional): Desired source name. Useful if you want to override the source name configured for the source.
-Placeholders `%{attr_name}` will be replaced with attribute value for `attr_name`.
+[Source templates](#source-templates) are going to be applied.
 - `source_host` (optional): Desired host name. Useful if you want to override the source host configured for the source.
-Placeholders `%{attr_name}` will be replaced with attribute value for `attr_name`.
+[Source templates](#source-templates) are going to be applied.
 - `timeout` (default = 5s): Is the timeout for every attempt to send data to the backend.
 Maximum connection timeout is 55s.
 - `retry_on_failure`
@@ -35,7 +35,15 @@ Maximum connection timeout is 55s.
     - `num_seconds` is the number of seconds to buffer in case of a backend outage
     - `requests_per_second` is the average number of requests per seconds.
 
-Example:
+## Source Templates
+
+You can specify a template with an attribute for `source_category`, `source_name`, `source_host` or `graphite_template` using `%{attr_name}`.
+
+For example, when there is an attribute `my_attr`: `my_value`, `metrics/%{my_attr}` would be expanded to `metrics/my_value`.
+
+For `graphite_template`, in addition to above, `%{_metric_}` is going to be replaced with metric name.
+
+## Example Configuration
 
 ```yaml
 exporters: