Update Compiler-properties.md

Fix table formatting

docs/markdown/Compiler-properties.md

@@ -97,12 +97,12 @@ result = compiler.run(code, name : 'basic check')
 
 The `result` variable encapsulates the state of the test, which can be extracted with the following methods. The `name` keyword argument works the same as with `compiles`.
 
-Method | Return value
--------|----------------
-compiled | `True` if compilation succeeded. If `false` then all other methods return undefined values.
-returncode | The return code of the application as an integer
-stdout | Program's standard out as text.
-stderr | Program's standard error as text.
+| Method     | Return value
+| ------     | ------------
+| compiled   | `True` if compilation succeeded. If `false` then all other methods return undefined values.
+| returncode | The return code of the application as an integer
+| stdout     | Program's standard out as text.
+| stderr     | Program's standard error as text.
 
 Here is an example usage: