Fix assembly formatting and highlighting

README.md

@@ -290,21 +290,21 @@ converted to instructions through the Instruction Selection process.
 For example, Instruction Selection produces the following output for the IR
 above:
 
-```mips
+```asm
 PROCEDURE L0
 L0: 
 L2:
-addi t0, r0, 7
-sw t0, ~4(t25)
-addi t1, r0, 9
-sw t1, ~8(t25)
-addi t2, r0, 3
-sw t2, ~12(t25)
-lw t4, ~4(t25)
-lw t5, ~8(t25)
-add t3, t4, t5
-sw t3, ~12(t25)
-j L1
+    addi t0, r0, 7
+    sw t0, ~4(t25)
+    addi t1, r0, 9
+    sw t1, ~8(t25)
+    addi t2, r0, 3
+    sw t2, ~12(t25)
+    lw t4, ~4(t25)
+    lw t5, ~8(t25)
+    add t3, t4, t5
+    sw t3, ~12(t25)
+    j L1
 L1:
 END L0
 ```
@@ -392,7 +392,7 @@ end
 
 Compiles to the following MIPS assembly with correct physical registers allocated:
 
-```mips
+```asm
 .text
     j    L0
 .text