pacman-u: add alias page; pacman-upgrade: update page (#15179)

pages/linux/pacman-u.md

@@ -0,0 +1,7 @@
+# pacman -U
+
+> This command is an alias of `pacman --upgrade`.
+
+- View documentation for the original command:
+
+`tldr pacman upgrade`

pages/linux/pacman-upgrade.md

@@ -6,24 +6,24 @@
 
 - Install one or more packages from files:
 
-`sudo pacman --upgrade {{path/to/package1.pkg.tar.zst}} {{path/to/package2.pkg.tar.zst}}`
+`sudo pacman -U {{path/to/package1.pkg.tar.zst}} {{path/to/package2.pkg.tar.zst}}`
 
 - Install a package without prompting:
 
-`sudo pacman --upgrade --noconfirm {{path/to/package.pkg.tar.zst}}`
+`sudo pacman -U --noconfirm {{path/to/package.pkg.tar.zst}}`
 
 - Overwrite conflicting files during a package installation:
 
-`sudo pacman --upgrade --overwrite {{path/to/file}} {{path/to/package.pkg.tar.zst}}`
+`sudo pacman -U --overwrite {{path/to/file}} {{path/to/package.pkg.tar.zst}}`
 
-- Install a package, skipping the dependency version checks:
+- Install a package, skipping the dependency [(d)] version checks:
 
-`sudo pacman --upgrade --nodeps {{path/to/package.pkg.tar.zst}}`
+`sudo pacman -Ud {{path/to/package.pkg.tar.zst}}`
 
-- List packages that would be affected (does not install any packages):
+- Fetch and [p]rint packages that would be affected by upgrade (does not install any packages):
 
-`pacman --upgrade --print {{path/to/package.pkg.tar.zst}}`
+`pacman -Up {{path/to/package.pkg.tar.zst}}`
 
 - Display help:
 
-`pacman --upgrade --help`
+`pacman -U --help`