Add zsh and bash completions for x

src/etc/completions/x.bash

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+_x_completions()
+{
+  if [ "${#COMP_WORDS[@]}" -le "2" ]; then
+	COMPREPLY=($(compgen -W "build check clippy fix fmt test bench doc clean dist install run setup" "${COMP_WORDS[1]}"))
+    return
+  else
+    compopt -o nospace
+    local cur=${COMP_WORDS[COMP_CWORD]}
+    local top=$(git rev-parse --show-toplevel 2>/dev/null || return)
+    COMPREPLY=$(cd $top && compgen -f -- "$cur")
+  fi
+}
+complete -F _x_completions x

src/etc/completions/x.zsh

@@ -0,0 +1,13 @@
+#!/usr/bin/env zsh
+
+_x_completions()
+{
+  local line
+  local top=$(git rev-parse --show-toplevel 2>/dev/null || return)
+  cd "${top}"
+  _arguments -C \
+    "1:subcommand:(build check clippy fix fmt test bench doc clean dist install run setup)" \
+    "*:files:_files"
+  cd "${OLDPWD}"
+}
+compdef _x_completions x