This commit adds changes to document string schema custom attributes. Community at truecharts raised a concern where they are not sure how the regex works for valid_char string attribute, so the changes introduced in this commit address the concerns and while we are here document other custom string options as well.
This commit documents change how chart devs can have certain workloads to be scaled down before taking a snapshot of the application's volumes on an upgrade of the application to a newer catalog item version.
