On `secureli init`, set pre-commit hooks to run `secureli scan`

[gabenegron]

As part of this story, also write .git/hooks/pre-commit script

[stujfiter]

As a user, I want seCureLI to install and configure pre-commit (the tool) for me based on the languages detected in my repository so that I don't have to separately install and configure pre-commit (the tool)

Acceptance Criteria:

• seCureLI installs pre-commit (Already implemented)
• seCureLI adds .pre-commit-config.yaml with reasonable language specific defaults (Already implemented)
• seCureLI configures git pre-commit hooks to call secureli scan prior to each commit.

Answered questions:

• Q: Does pip install pre-commit as a dependency? Homebrew appears to. A: yes pip and homebrew (linuxbrew) both install pre-commit

[gabenegron]

@stujfiter Let's talk about the 3rd bullet point in this story in our next standup meeting