Remove numbers at the start of slugs when converting to mod ID (#897)

* Remove numbers at the start of slugs when converting to mod ID

* If mod id is all digits, replace with project ID

plugins/fileUtils.js

@@ -376,9 +376,12 @@ export const createDataPackVersion = async function (
     ? version.version_number
     : `1-${version.version_number}`
 
+  const targetStartingDigitsRegex = /^(\d+)(\D+)$/g
   const newSlug = `${project.slug
     .replace('-', '_')
     .replace(/\W/g, '')
+    .replace(targetStartingDigitsRegex, '$2')
+    .replace(/^(\d+)$/g, project.id.replace(targetStartingDigitsRegex, '$2'))
     .substring(0, 63)}_mr`
 
   const iconPath = `${project.slug}_pack.png`