688f665a5e526fda0fb797bf617412fe9cbe64fd Scripts and tools & Docs: Used #!/usr/bin/env bash instead of obsolete #!/bin/bash, added linting for .sh files shebang and updated the Developer Notes. (vim88)
Pull request description:
As it was discussed in [#13510](https://github.com/bitcoin/bitcoin/pull/13510), it is better to use `#!/usr/bin/env bash` instead of `#!/bin/bash`.
Tree-SHA512: 25f71eb9a6a0cdc91568b5c6863205c5fe095f77a69e633503a2ac7805bd9013af8538e538c0c666ce96a28e3f43ce7a8df5f08d4ff007723bb588d85674f2da