Support for properties files

[Lucas3oo]

• What's the file's extension?
  *.properties

• What's the file's Uniform Type Identifier (output of mdls -name kMDItemContentType /path/to/your/file)?
  $ mdls -name kMDItemContentType tmp/stg17.properties
  kMDItemContentType = "dyn.ah62d4rv4ge81a6xtsbw1e7dmqz3u"

• What kind of preview do you expect? How can it be generated?
  It is a source code type of text file so any syntax can be used.

Sample content:
#Spring Profile
spring.profiles.active=swagger

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