Need to refactor configuration file syntax.

Propose the following:

git:
  - path: path/to/repo
    processors:
      - mode: [ head | each | all ]
        file: path/to/outputfile
        template: "template string"
  - path:
    processors:
      - mode: [ head | each | all ]
        file: path/to/outputfile
        template: "template string"
exec:
  - path: path/to/search
    pattern: *.md
    command: "echo {{ . }}"

Allows for:

Multiple repositories
- Hugo publication pipelines containing multiple repos may be rare, but I already have one such case.
Multiple actions per repository
Moves Git mode from key to value, simplifies parsing and sanity checking.
Clarifies "processors" as "exec" handlers.
Each handler type starts as an array (git, exec).

jason-dour / hugo-preproc

Need to refactor configuration file syntax. #5