Better research history with arrow keys

This change enables UP-arrow and DOWN-arrow full-line history completion.
For example, if you write `git clone` and press UP:

- Before this change,
  it will use the last command that starts with `git`.

- After this change,
  it will use the last command that starts with `git clone`.

lib/key-bindings.zsh

@@ -27,11 +27,17 @@ if [[ "${terminfo[knp]}" != "" ]]; then
   bindkey "${terminfo[knp]}" down-line-or-history     # [PageDown] - Down a line of history
 fi
 
+# start typing + [Up-Arrow] - fuzzy find history forward
 if [[ "${terminfo[kcuu1]}" != "" ]]; then
-  bindkey "${terminfo[kcuu1]}" up-line-or-search      # start typing + [Up-Arrow] - fuzzy find history forward
+  autoload -U up-line-or-beginning-search
+  zle -N up-line-or-beginning-search
+  bindkey "${terminfo[kcuu1]}" up-line-or-beginning-search
 fi
+# start typing + [Down-Arrow] - fuzzy find history backward
 if [[ "${terminfo[kcud1]}" != "" ]]; then
-  bindkey "${terminfo[kcud1]}" down-line-or-search    # start typing + [Down-Arrow] - fuzzy find history backward
+  autoload -U down-line-or-beginning-search
+  zle -N down-line-or-beginning-search
+  bindkey "${terminfo[kcud1]}" down-line-or-beginning-search
 fi
 
 if [[ "${terminfo[khome]}" != "" ]]; then