Get output text from shell commands, part 1

[Taitava]

Discussed in https://github.com/Taitava/obsidian-shellcommands/discussions/16

This issue is meant for implementing part of the features mentioned in the above discussion. This does not mean that other features would not be implemented later. This is just a way to split work into well managed parts.

Implement these channels for shell command output (stdout):

• [x] Ignore the output. Just like it's currently done. (Will be the default option).
• [x] A balloon on the top right corner. Suitable for multirow but short outputs, like a list of around five files in a folder.
• [x] Insert into the current file at caret location. Can also replace text if something was selected at the time of executing a command.

[Taitava]

Still needed:

• [x] Handle stderr
• [x] Write documentation
• [x] Test, test, test!

[Taitava]

Implemented & released in 0.5.0.

[FelipeRearden]

Working perfect on:

Version 0.5.0 MacOS 11.1 Obsidian 0.12.15

Additional information about 0.5.0 here #16.