FIX(composer.json): fix license + add some usefull properties

composer.json schema
https://getcomposer.org/doc/04-schema.md

Refs: #5

.gitattributes

@@ -130,7 +130,7 @@ TODO              text
 .nycrc            text
 .prettierrc       text
 .prettierignore   text
-*.lock            text -diff
+*.lock            text
 package-lock.json text -diff
 *.npmignore       text
 *.toml            text

webapp/composer.json

 {
     "type": "project",
-    "license": "proprietary",
+    "name": "adullact/comptoir",
+    "description": "Comptoir_du_libre aims at connecting local governments, libre softwares and services providers via a lightweigh web interface",
+    "homepage": "https://comptoir-du-libre.org/",
+    "license": "AGPL-3.0-or-later",
+    "support": {
+        "source": "https://gitlab.adullact.net/Comptoir/comptoir",
+        "issues": "https://gitlab.adullact.net/Comptoir/comptoir/issues"
+    },
     "require": {
         "php": "^7.2.5",
         "ext-ctype": "*",
@@ -80,5 +87,8 @@
             "allow-contrib": false,
             "require": "5.0.*"
         }
-    }
+    },
+    "minimum-stability": "stable",
+    "prefer-stable": true
+
 }

webapp/composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "f0aa134c748f7bb4398f0b93f0f19bb9",
+    "content-hash": "5ce838d303cb26ce5438b31e0eb53541",
     "packages": [
         {
             "name": "doctrine/annotations",
@@ -6743,7 +6743,7 @@
     "aliases": [],
     "minimum-stability": "stable",
     "stability-flags": [],
-    "prefer-stable": false,
+    "prefer-stable": true,
     "prefer-lowest": false,
     "platform": {
         "php": "^7.2.5",