add language_dev constant

this constant, if enabled, will display MISSING STRING: string_id
if disabled, it will display the english version of string string_id

src/lang/bg.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/es.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/fa.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "rtl"

src/lang/fr.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/gl.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/it.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/ms.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lang/ru.js

@@ -1,5 +1,7 @@
 const data = {...require("./base")}
 const {pug} = require("./utils/functions")
+const constants = require("../lib/constants")
+if (!constants.language_dev) Object.assign(data, require("./en.js"))
 
 ;(() => {
 	data.meta_direction = "ltr"

src/lib/constants.js

@@ -290,7 +290,10 @@ let constants = {
 	additional_routes: [],
 
 	database_version: 10,
-	actually_backup_on_database_upgrade: true
+	actually_backup_on_database_upgrade: true,
+
+	// enable this to display: "MISSING STRING: string_id" instead of the English version for all untranslated strings
+	language_dev: false
 }
 
 // Override values from config and export the result