Add "gdw" for git diff --word-diff

* Sometimes helpful to see changes inline
* Potential to tweak further with better regex (maybe detect similar char types so diff can be more granular)

git.scmbrc.example

@@ -47,6 +47,7 @@ git_reset_hard_alias="grsh"
 git_rm_alias="grm"
 git_blame_alias="gbl"
 git_diff_alias="gd"
+git_diff_word_alias="gdw"
 git_diff_cached_alias="gdc"
 # 3. Standard commands
 git_clone_alias="gcl"