Update the Bash example with the multi source files option

* Usage of $easyoptions_include in bash/example.sh
* The example sourced scripts bash/some_sourced_lib.sh and bash/that_other_lib.sh

bash/example.sh

@@ -21,8 +21,9 @@
 ##                             format.
 
   script_dir=$(dirname "$BASH_SOURCE")
-  source "${script_dir}/../easyoptions" || exit # Ruby implementation
-# source "${script_dir}/easyoptions.sh" || exit # Bash implementation, slower
+  easyoptions_include="${script_dir}/some_sourced_lib.sh ${script_dir}/that_other_lib.sh"
+# source "${script_dir}/../easyoptions" || exit # Ruby implementation
+  source "${script_dir}/easyoptions.sh" || exit # Bash implementation, slower
 
 # Boolean and parameter options
 [[ -n "$some_option"  ]] && echo "Option specified: --some-option"
@@ -33,3 +34,9 @@
 for argument in "${arguments[@]}"; do
     echo "Argument specified: $argument"
 done
+
+source "${script_dir}/some_sourced_lib.sh"
+some-lib-feature
+
+source "${script_dir}/that_other_lib.sh"
+that-other-feature

bash/some_sourced_lib.sh

@@ -0,0 +1,5 @@
+##     -s, --some-lib-option   This is an additional option.
+some-lib-feature()
+{
+    [[ -n "$some_lib_option" ]] && echo "Some lib option: $some_lib_option"
+}

bash/that_other_lib.sh

@@ -0,0 +1,6 @@
+##     -t, --that-option       That is the option.
+that-other-feature()
+{
+    [[ -n "$that_option" ]] && echo "That other option: $that_option"
+}
+