Fix spaces for README

README.md

@@ -26,17 +26,17 @@ If you have a comment or suggestion, please open an [issue](https://github.com/d
     3.5c [Authentication key](#35c-authentication-key)  
   3.6 [Check your work](#36-check-your-work)  
   3.7 [Export keys](#37-export-keys)  
-		3.7a [Linux/macOS](#37a-linuxmacos)  
-		3.7b [Windows](#37b-windows)  
+    3.7a [Linux/macOS](#37a-linuxmacos)  
+    3.7b [Windows](#37b-windows)  
   3.8 [Backup everything](#38-backup-everything)  
-		3.8a [Linux/macOS](#38a-linuxmacos)  
-		3.8b [Windows](#38b-windows)  
+    3.8a [Linux/macOS](#38a-linuxmacos)  
+    3.8b [Windows](#38b-windows)  
   3.9 [Configure YubiKey](#39-configure-yubikey)  
-		3.9a [Linux/macOS](#39a-linuxmacos)  
-		3.9b [Windows](#39b-windows)  
+    3.9a [Linux/macOS](#39a-linuxmacos)  
+    3.9b [Windows](#39b-windows)  
   3.10 [Configure smartcard](#310-configure-smartcard)  
-	  3.10a [Change PINs](#310a-change-pins)  
-	  3.10b [Set card information](#310b-set-card-information)  
+    3.10a [Change PINs](#310a-change-pins)  
+    3.10b [Set card information](#310b-set-card-information)  
   3.11 [Transfer keys](#311-transfer-keys)  
     3.11a [Signature key](#311a-signature-key)  
     3.11b [Encryption key](#311b-encryption-key)  
@@ -60,7 +60,7 @@ If you have a comment or suggestion, please open an [issue](https://github.com/d
     4.5c [Copy public key to server](#45c-copy-public-key-to-server)  
     4.5d [Connect with public key authentication](#45d-connect-with-public-key-authentication)  
   4.6 [SSH - Windows](#46-ssh---windows)  
-	4.6a [GitHub](#46a-github)  
+    4.6a [GitHub](#46a-github)  
   4.7 [Requiring touch to authenticate](#47-requiring-touch-to-authenticate)  
   4.8 [OpenBSD](#48-openbsd)  
 5. [Troubleshooting](#5-troubleshooting)