docs: remove -u from yay commands (#1018)

README.md

@@ -427,7 +427,7 @@ echo 'source /usr/local/opt/powerlevel10k/powerlevel10k.zsh-theme' >>! ~/.zshrc
 ### Arch Linux
 
 ```zsh
-yay -Sy --noconfirm zsh-theme-powerlevel10k-git
+yay -S --noconfirm zsh-theme-powerlevel10k-git
 echo 'source /usr/share/zsh-theme-powerlevel10k/powerlevel10k.zsh-theme' >>! ~/.zshrc
 ```
 
@@ -613,7 +613,7 @@ The command to update Powerlevel10k depends on how it was installed.
 | [Zplugin](#zplugin)       | `zplugin update`                                            |
 | [Zinit](#zinit)           | `zinit update`                                              |
 | [Homebrew](#homebrew)     | `brew update && brew upgrade`                               |
-| [Arch Linux](#arch-linux) | `yay -Syu --noconfirm --needed zsh-theme-powerlevel10k-git` |
+| [Arch Linux](#arch-linux) | `yay -S --noconfirm zsh-theme-powerlevel10k-git`            |
 
 **IMPORTANT**: Restart Zsh after updating Powerlevel10k. [Do not use `source ~/.zshrc`](
   #weird-things-happen-after-typing-source-zshrc).