More backslash escape fixes

docs/migration.rst

@@ -18,11 +18,11 @@ Fix handling of string and bytes default values
 -----------------------------------------------
 
 **Rationale:** Previously nanopb didn't properly decode special character
-escapes like \200 emitted by protoc. This caused these escapes to end up
+escapes like \\200 emitted by protoc. This caused these escapes to end up
 verbatim in the default values in .pb.c file.
 
-**Changes:** Escapes are now decoded, and e.g. "\200" or "\x80" results in
-{0x80} for bytes field and "\x80" for string field.
+**Changes:** Escapes are now decoded, and e.g. "\\200" or "\\x80" results in
+{0x80} for bytes field and "\\x80" for string field.
 
 **Required actions:** If code has previously relied on '\\' in default value
 being passed through verbatim, it must now be changed to '\\\\'.