spelling

Co-authored-by: Marc Cenac <547446+mrcnc@users.noreply.github.com>

Author: julienledem

proposals/README.md

@@ -27,7 +27,7 @@ Make sure you consider the [requirements document](https://docs.google.com/docum
 *Transition:* There is enough clarity on the spec for the new feature and we have identified the reference implementations to be implemented to be able to release.
 
 ### Implementation
-Once we have reached enough consensus on the formalized spec change and validated it through the POC, we should have a clear idea of whether we want to pursue the implementation accross the ecosystem. 
+Once we have reached enough consensus on the formalized spec change and validated it through the POC, we should have a clear idea of whether we want to pursue the implementation across the ecosystem. 
 At this stage we should finalize a formal spec contribution to parquet-format and we need to meet the contribution guidelines to consider the implementation finished. 
 See [CONTRIBUTING guidelines](https://github.com/apache/parquet-format/blob/master/CONTRIBUTING.md#additionschanges-to-the-format).