Fix small typo in README.md

Co-authored-by: Dominik Rosiek <[email protected]>

exporter/exporterhelper/README.md

@@ -22,7 +22,7 @@ The following configuration options can be modified:
     - `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.
   - `persistent_storage_enabled` (default = false): When set, enables persistence via a file storage extension 
-    (note, `unable_unstable` build tag needs to be enabled first, see below for more details)
+    (note, `enable_unstable` build tag needs to be enabled first, see below for more details)
 - `resource_to_telemetry_conversion`
   - `enabled` (default = false): If `enabled` is `true`, all the resource attributes will be converted to metric labels by default.
 - `timeout` (default = 5s): Time to wait per individual attempt to send data to a backend.
@@ -34,7 +34,7 @@ The full list of settings exposed for this helper exporter are documented [here]
 **Status: under development**
 
 > :warning: The capability is under development and currently can be enabled only in OpenTelemetry
-> Collector Contrib with `unable_unstable` build tag set. 
+> Collector Contrib with `enable_unstable` build tag set. 
 
 When `persistent_storage_enabled` is set to true, the queue is being buffered to disk using 
 [file storage extension](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/extension/storage/filestorage).