fix: Readme.md is outdated in regards of decorator names

### Description

The decorators in the Readme.md Doc still refers to the naming from 0.3.x 
It still contains @TransfromPlainToClass which was renamed to @TransformPlainToInstance
 
### Expected behavior
The decorators refer to naming of the release 0.5.x
e.g. @TransformPlainToInstance

### Actual behavior
The decorators refer to naming of the release 0.3.x
e.g. @TransfromPlainToClass