Improvements to Self-Managed deployment table descriptions

[mesellings]

This issue was prompted by the work for #4118.

For the description columns in the tables:

• Standardise the descriptions to make them less passive. For example, 'When true, Importer module is enabled" > "Enable the Importer module".
• The use of "whether" could be changed to use "if" as per the Camunda writing style guide: https://camunda.com/brand/writing-style-guide/.

These files are affected, there may be other tables in these docs that are also affected?

• https://docs.camunda.io/docs/next/self-managed/operate-deployment/importer-and-archiver/
• https://docs.camunda.io/docs/next/self-managed/tasklist-deployment/importer-and-archiver/
• https://docs.camunda.io/docs/next/self-managed/zeebe-deployment/configuration/gateway-config/
• https://docs.camunda.io/docs/next/self-managed/zeebe-deployment/configuration/broker-config/

[mesellings]

FYI @akeller