Merge xpub-theme from xpub monorepo into pubsweet monorepo as @pubsweet/theme

packages/theme/package.json

+{
+  "name": "@pubsweet/theme",
+  "version": "0.1.0",
+  "description": "CSS for PubSweet apps and styleguides",
+  "main": "src",
+  "license": "MIT",
+  "dependencies": {
+    "cokourier-prime-sans": "git+https://gitlab.coko.foundation/julientaq/cokourier-sans-prime.git",
+    "typeface-fira-mono": "^0.0.43",
+    "typeface-fira-sans": "^0.0.43",
+    "typeface-fira-sans-condensed": "^0.0.43",
+    "typeface-vollkorn": "^0.0.43"
+  },
+  "dependencies_disabled": {
+    "pubsweet-fira": "^0.0.3"
+  }
+}

packages/theme/src/index.js

+import 'typeface-fira-mono'
+import 'typeface-fira-sans'
+import 'typeface-fira-sans-condensed'
+import 'typeface-vollkorn'
+// import 'pubsweet-fira'
+import 'cokourier-prime-sans'
+
+import './variables.css'

packages/theme/src/variables.css

+:root {
+  /* brand colors */
+  --color-primary: #0d78f2;
+
+  /* colors for interactions */
+  --color-danger: #ff2d1a;
+  --color-warning: #ee7600;
+  --color-valid: #00bf05;
+  --color-pending: #aaa;
+
+  /* fonts for the different views */
+  --font-author: 'Vollkorn', serif;
+  --font-reviewer: 'Kocourier Prime Sans', monospace;
+  --font-interface: 'Fira Sans Condensed', sans-serif;
+  --font-mono: 'Fira Mono', monospace;
+}