Add Definition: Support empty consolidated definition files fixes #70

[christopherjsmith]

Fixes https://github.com/dominiclet/obsidian-note-definitions/issues/70

Root cause: file type identification was based on the first entry present in the file. Solution: Use file meta-data or plugin default to identify file type

Note: Will need the following files up versioning accordingly on merge before release is built.

• manifest.json
• versions.json

BRAT installable version: https://github.com/christopherjsmith/obsidian-note-definitions-ipad