add git config for delta and difftastic

.config/git/config.delta

@@ -0,0 +1,34 @@
+[core]
+	pager = delta
+
+[diff]
+	colorMoved = default
+
+[interactive]
+	diffFilter = delta --color-only
+
+[delta]
+	navigate = true
+	dark = true
+	max-line-length = 0
+	syntax-theme = none
+	line-numbers = true
+	hunk-header-style = omit
+	side-by-side = true
+
+	line-number-minus-style = "#b93741"
+	line-number-plus-style = "#37a44b"
+
+	minus-style = normal "#580000"
+	minus-emph-style = normal "#b93741"
+	plus-style = normal "#004900"
+	plus-emph-style = normal "#37a44b"
+
+	map-styles = \
+		bold purple => syntax "#450036", \
+		bold blue => syntax "#000057", \
+		bold cyan => syntax "#003850", \
+		bold yellow => syntax "#573d00"
+
+[merge]
+	conflictstyle = zdiff3

.config/git/config.difftastic

@@ -0,0 +1,2 @@
+[diff]
+	external = difft