doc/opcode.md: table reformatted.
@@ -23,7 +23,7 @@ sign) of operands.
## table.1 Instruction Table
| Instruction Name | Operand type | Semantics |
-|------------------|--------------|--------------------------------------------------------|
+|------------------|--------------|----------------------------------------------------------|
| `OP_NOP` | `-` | `no operation` |
| `OP_MOVE` | `BB` | `R(a) = R(b)` |
| `OP_LOADL` | `BB` | `R(a) = Pool(b)` |
@@ -128,4 +128,4 @@ sign) of operands.
| `OP_EXT2` | `-` | `make 2nd operand 16bit` |
| `OP_EXT3` | `-` | `make 1st and 2nd operands 16bit` |
| `OP_STOP` | `-` | `stop VM` |
-|------------------|--------------|--------------------------------------------------------|
+|------------------|--------------|----------------------------------------------------------|
