Switch from difft to delta

Difftastic is too hard to read the diffs for a colorblind person. Delta
has much more readable diffs because it uses a background color to
indicate changes.

.gitconfig

@@ -36,14 +36,24 @@
 
 [core]
     editor = vim
+    pager = delta
     attributesfile = /home/tgrosinger/.gitattributes
     excludesfile = /home/tgrosinger/.gitignore_global
 
+[interactive]
+    diffFilter = delta --color-only
+
 [push]
     default = simple
 
 [diff]
-    external = difft
+    colorMoved = default
+
+[delta]
+    navigate = true
+    light = true
+    side-by-side = true
+    line-numbers = true
 
 [branch]
     autosetuprebase = always

install.sh

@@ -89,6 +89,7 @@ function performSetup() {
     linkBin "${BIN_DIR}/bat-0.18.2" "bat"
     linkBin "${BIN_DIR}/jq-1.6" "jq"
     linkBin "${BIN_DIR}/difft-0.38.0" "difft"
+    linkBin "${BIN_DIR}/delta-0.14.0" "delta"
     linkBin "${BIN_DIR}/dive-0.10.0" "dive"
 
     echo "Linking scripts"