Adds pager option and uses $PAGER environment variable

Due to bat also reading the $PAGER environment variable, I first look to
see if bat is available. If it is, I use that. If it isn't, I use the
$PAGER environment variable. If that's not available, I use cat.

I also added the --editor flag to the help output which had clearly been
missed

Close #12

kb

@@ -89,6 +89,11 @@ args=()
 dataDir="${XDG_DATA_HOME:=$HOME/.local/share}/kb/"
 sqliteFile=""
 editor="${EDITOR:=vim}"
+if type -p bat > /dev/null 2>&1; then
+	pager="bat"
+else
+	pager="${PAGER:=cat}"
+fi
 
 # Check for Dependencies
 # -----------------------------------
@@ -373,6 +378,8 @@ usage() {
 	-h, --help              Display this help and exit
 	--data <directory>      The knowledgebase data dir
 	--sqlite <file>         The sqlite file (default to <data>/knowledgebase.sqlite3
+	--editor <editor>       The editor to use (default $EDITOR or vim)
+	--pager <editor>        The pager to use (default bat or $PAGER or cat)
 	--nogit                 Don't run git commands
 	--version               Output version information and exit
 
@@ -446,6 +453,7 @@ while [[ $1 = -?* ]]; do
 		--data) dataDir="$2"; shift ;;
 		--sqlite) sqliteFile="$2"; shift ;;
 		--editor) editor="$2"; shift ;;
+		--pager) pager="$2"; shift ;;
 		--nogit) dogit=0 ;;
 		--) shift; break ;;
 		*) die "invalid option: '$1'." ;;