highlight call for donations

source/contributing/documentation.md

@@ -5,7 +5,9 @@ Documentation contributions should follow the [style guide](./style-guide.md).
 
 Feel free to in touch with the [Nix documentation team](https://nixos.org/community/teams/documentation) if you want to help out.
 
+:::{attention}
 If you cannot contribute time, consider [donating to the NixOS Foundation's documentation project on Open Collective](https://opencollective.com/nixos/projects/documentation-project) to fund ongoing maintenance and development of reference documentation and learning materials.
+:::
 
 ## Documentation framework
 We aim to build our documentation according to the [Diataxis][diataxis] framework, which divides documentation into four categories:

source/contributing/how-to-contribute.md

@@ -26,9 +26,12 @@ We're working on it.
 You can help and improve the situation for everyone by immediately solving problems with the contribution workflow as you encounter them.
 While this may slow you down with addressing your original concern, it will make it a lot easier for anyone to make meaningful contributions in the future, and lead to better code and documentation in the long run.
 
+:::{attention}
 If you cannot contribute time, consider [donating to the NixOS Foundation on Open Collective](https://opencollective.com/nixos).
+
 Currently the focus is on funding in-person events to share knowledge and grow the community of developers proficient with Nix.
-With enough budget, it would be possible to pay for ongoing maintenance and development of critical infrastructure and code – work that we cannot expect to be done by volunteers in the long run.
+With enough budget, it would be possible to pay for ongoing maintenance and development of critical infrastructure and code – demanding work that we cannot expect to be done by volunteers indefinitely.
+:::
 
 ## Report an issue