zsh: Switch from powerlevel10k to pure prompt

Switched theme of zsh, just to declutter a little and make startup
slightly faster.

Removed nvm from automatically initializing to majorly speed up zsh
startup times - removing around 750ms on my system.
TODO could potentially move to a conditional startup system, in which
nvm only gets sourced on its first invocation or similar workarounds.

bootstrap/packages.txt

@@ -15,7 +15,6 @@ bc
 biber
 bibtool
 bison
-chromium
 dhcpcd
 dialog
 diff-so-fancy
@@ -47,7 +46,6 @@ iputils
 jabref-latest
 jpdftweak
 jq
-keybase-bin
 licenses
 linux-firmware
 linux-headers
@@ -86,7 +84,6 @@ paru
 pass
 pavolume
 pdfjs
-pia-tools
 picom
 pkgconf
 playerctl
@@ -152,7 +149,7 @@ xclip
 xorg-xev
 xorg-xinit
 xorg-xinput
-youtube-dlc
+youtube-dl
 
 # zsh plugins
 alias-tips-git
@@ -163,4 +160,4 @@ zathura-pdf-mupdf
 zsh-autosuggestions
 zsh-completions-git
 zsh-fast-syntax-highlighting-git
-zsh-theme-powerlevel10k-git
+zsh-pure-prompt