chore: minor auth related improvements (#4483)

* chore: show `(optional)` in label of non-required fields.

* chore: fix github auth button text color.

* chore: minor ui/ ux improvement in oauth options.

admin/components/common/controller-input.tsx

@@ -2,10 +2,10 @@
 
 import React, { useState } from "react";
 import { Controller, Control } from "react-hook-form";
-// ui
-import { Eye, EyeOff } from "lucide-react";
-import { Input } from "@plane/ui";
 // icons
+import { Eye, EyeOff } from "lucide-react";
+// ui
+import { Input } from "@plane/ui";
 // helpers
 import { cn } from "@/helpers/common.helper";
 
@@ -37,7 +37,9 @@ export const ControllerInput: React.FC<Props> = (props) => {
 
   return (
     <div className="flex flex-col gap-1">
-      <h4 className="text-sm text-custom-text-300">{label}</h4>
+      <h4 className="text-sm text-custom-text-300">
+        {label} {!required && "(optional)"}
+      </h4>
       <div className="relative">
         <Controller
           control={control}