feat: add the MJ plugin metadata and some docs

Note that the doc was written first,
as we followed the pattern: doc, test, code

It was pretty nice, and it helped a lot.

addons/majority_judgment/plugin.cfg

@@ -0,0 +1,7 @@
+[plugin]
+
+name="Majority Judgment Poll Toolkit"
+description="Majority Judgment poll resolution and display utilities."
+author="MieuxVoter"
+version="1.0"
+script="plugin.gd"

addons/majority_judgment/plugin.gd

@@ -0,0 +1,64 @@
+tool
+extends EditorPlugin
+
+"""
+
+Various utilities to help deliberate using Majority Judgment.
+
+
+Examples
+========
+
+They are unit-tested using WAT. (see `tests/` directory)
+WIP: Right now the `tests/` directory in not in the plugin itself.  We aim to.
+
+
+Features
+========
+
+A bunch of new References:
+
+- `MajorityJudgmentGrade`
+  A single grade, like Excellent or To Reject.
+  This is a class in order to handle localization.
+- `MajorityJudgmentGrading`
+  An ordered list of `MajorityJudgmentGrade`, from worst to best.
+- `MajorityJudgmentPoll`
+  Has a title, grades and candidates.
+- `MajorityJudgmentCandidate`
+  A candidate in a poll, receiving judgments.
+- `MajorityJudgmentParticipant`
+  Government of the People, by the People, for the People.
+- `MajorityJudgmentJudgment`
+  A grade given by a judge to a candidate.
+- `MajorityJudgmentTallier`
+  The algorithm computing the poll tally (and the order of candidates)
+  The default algorithm will follow Balinsky & Laraki suggestions
+  https://doi.org/10.1287/opre.2014.1269
+  https://gargantua.polytechnique.fr/siatel-web/app/linkto/?objectId=DOCF002100000008000000000000095700000000
+- `MajorityJudgmentPollTally`
+  Output of the tallier above.  Ordered candidate tallies, winner first.
+- `MajorityJudgmentCandidateTally`
+  Amounts of judgments per grade for a specific candidate.
+
+They all are `class_name`d, so they are polluting the global namespace,
+but their name should be unique enough, with the prefix `MajorityJudgment`.
+
+If it causes you pain, you're welcome to open an issue to discuss about it.
+
+
+MajorityJudgmentLinearResultsControl
+------------------------------------
+TODO
+
+
+"""
+
+
+#func _enter_tree():
+#	add_custom_type("MajorityJudgmentLinearResultsControl", "Control", load("res://addons/majority_judgment/MajorityJudgmentLinearResultsControl.gd"), load("res://addons/majority_judgment/MajorityJudgmentLinearResultsControl.svg"))
+
+
+#func _exit_tree():
+#	remove_custom_type("MajorityJudgmentLinearResultsControl")
+