Adding more brush descriptions

Also renamed the cat, dog, and squirrel filenames so they
appear next to each other in the brush list.

data/brushes/arrow.txt

@@ -0,0 +1 @@
+The arrow points the direction you draw.

data/brushes/arrow_triangles.txt

@@ -0,0 +1 @@
+The triangle points the direction you draw.

data/brushes/critter_dog.txt

@@ -0,0 +1 @@
+The dog chases where you draw.

data/brushes/critter_kuroneko.txt

@@ -0,0 +1 @@
+The cat chases where you draw.

data/brushes/critter_squirrel.txt

@@ -0,0 +1 @@
+The squirrel runs where you draw.

data/brushes/footprints-human-shoes.txt

@@ -0,0 +1 @@
+Paint footsteps with shoes on your picture.

data/brushes/footprints-human.txt

@@ -0,0 +1 @@
+Paint barefoot footsteps on your picture.

data/brushes/footprints-paws.txt

@@ -0,0 +1 @@
+Paint pawprints on your picture.

data/brushes/inksplat.txt

@@ -0,0 +1 @@
+Paint random ink splats on your picture.

data/brushes/lines-angled.txt

@@ -0,0 +1 @@
+Hash marks that draw perpendicular to the direction your painting.