Add Firefox extension build (#277)

browser/background.js

@@ -0,0 +1,48 @@
+/*
+ * Vencord, a modification for Discord's desktop app
+ * Copyright (c) 2022 Linnea Gräf
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+function setContentTypeOnStylesheets(details) {
+    if (details.type === "stylesheet") {
+        details.responseHeaders = details.responseHeaders.filter(it => it.name.toLowerCase() !== 'content-type');
+        details.responseHeaders.push({ name: "Content-Type", value: "text/css" });
+    }
+    return { responseHeaders: details.responseHeaders };
+}
+
+var cspHeaders = [
+    "content-security-policy",
+    "content-security-policy-report-only",
+];
+
+function removeCSPHeaders(details) {
+    return {
+        responseHeaders: details.responseHeaders.filter(header =>
+            !cspHeaders.includes(header.name.toLowerCase()))
+    };
+}
+
+
+
+
+browser.webRequest.onHeadersReceived.addListener(
+    setContentTypeOnStylesheets, { urls: ["https://raw.githubusercontent.com/*"] }, ["blocking", "responseHeaders"]
+);
+
+browser.webRequest.onHeadersReceived.addListener(
+    removeCSPHeaders, { urls: ["https://raw.githubusercontent.com/*", "*://*.discord.com/*"] }, ["blocking", "responseHeaders"]
+);

browser/manifestv2.json

@@ -0,0 +1,33 @@
+{
+    "manifest_version": 2,
+    "name": "Vencord Web",
+    "description": "The Vencord Client Mod for Discord Web.",
+    "version": "1.0.0",
+    "author": "Vendicated",
+    "homepage_url": "https://github.com/Vendicated/Vencord",
+    "permissions": [
+        "webRequest",
+        "webRequestBlocking",
+        "*://*.discord.com/*",
+        "https://raw.githubusercontent.com/*"
+    ],
+    "content_scripts": [
+        {
+            "run_at": "document_start",
+            "matches": [
+                "*://*.discord.com/*"
+            ],
+            "js": [
+                "content.js"
+            ]
+        }
+    ],
+    "web_accessible_resources": [
+        "dist/Vencord.js"
+    ],
+    "background": {
+        "scripts": [
+            "background.js"
+        ]
+    }
+}