Standardized license file

[platan]

Problem is described in #1666
GitHub is using https://github.com/benbalter/licensee in license detection (https://blog.github.com/2016-09-21-license-now-displayed-on-repository-overview/)

Current state

# branch master 
git --no-pager log --format="%H" -n 1
345d6222fc85af659b69847567e6f851d835fb0e

licensee detect LICENSE.md           
License:        NOASSERTION
Matched files:  LICENSE.md
LICENSE.md:
  Content hash:  1f1af19a4e586556c57466d4ec1a90f7ecaf460b
  License:       NOASSERTION

1st attempt
I've removed non standard fragment in out license file, diff https://github.com/badges/shields/compare/master...platan:standardized-license-1?expand=1

licensee detect LICENSE.md
License:        NOASSERTION
Matched files:  LICENSE.md
LICENSE.md:
  Content hash:  506c59e044a13782f7794e05a1090edc53091b40
  License:       NOASSERTION
  Closest non-matching licenses:
    CC0-1.0 similarity:  97.44%

2nd attempt
I've removed non standard fragment + I've changed license name (name from https://choosealicense.com/licenses/cc0-1.0/), diff https://github.com/platan/shields/compare/master...platan:standardized-license-2?expand=1

licensee detect LICENSE.md           
CC0 1.0 Universal
https://choosealicense.com/licenses/cc0-1.0/
License:        CC0-1.0
Matched files:  LICENSE.md
LICENSE.md:
  Content hash:  705e13a9e0c173fe8dbeb3a56ed57022550534d5
  Confidence:    98.01%
  Matcher:       Licensee::Matchers::Dice
  License:       CC0-1.0
  Closest non-matching licenses:
    CC0-1.0 similarity:  98.01%

3rd attempt - this PR
I've moved LICENSE.md to LICENSE and I've put content from https://choosealicense.com/licenses/cc0-1.0/ in it.

licensee detect LICENSE.md           
License:        CC0-1.0
Matched files:  LICENSE
LICENSE:
  Content hash:  83624ed81a5eea4456349757fe58ac7f721c154e
  Confidence:    100.00%
  Matcher:       Licensee::Matchers::Exact
  License:       CC0-1.0

After merge GH should detect our license properly. It does not do it on branch https://github.com/platan/shields/blob/standardized-license-3/LICENSE

[shields-ci]

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[chris48s]

Thanks for having a look at this 👍 Sounds like it was a bit more fiddly than it needed to be

[shields-deployment]

This pull request was merged to master branch. This change is now waiting for deployment, which will usually happen within a few days. Stay tuned by joining our #ops channel on Discord!

After deployment, changes are copied to gh-pages branch:

[platan]

It works :-) https://github.com/badges/shields/blob/master/LICENSE