Correct install version for Cargo

Dependencies

• [2] U4YBPVOP cargo install pijul: get the right version without constantly updating the manual
• [3] XDGLFBST version 1.0.0-alpha.24
• [4] BA5KMNO5 Updating installation instructions
• [5] OSJ2HIDP Version 1.0.0-alpha.10
• [6] I26FNFRT Latest release
• [7] SCSV2FNS Reboot
• [8] ONXLUQLI Add install instructions for arch
• [9] BRV6TU4B Turning the Installation page more beginner-friendly

Change contents

• replacement in src/installing.md at line 51
  [3.308207]→[2.0:42](∅→∅)
  − cargo install pijul --version 1.0.0-alpha
  [3.308207]

  [3.233]
  + cargo install pijul --version "~1.0.0-alpha"