How to convert schema from text file to scala dataframe

Question

We have text file having below data :

String Col1
String Col2
List <Object> Col3 [
     String Col3_1
     String Col3_2
]
String Col4
String Col5

We need to convert this to Scala Schema as :

val Schema = new StructType()
.add("Col1",StringType)
.add("Col2",StringType)
.add("Col3",StructType)
.add("Col4",StringType)
.add("Col5",StringType)

The data would be nested json and schema will keep evolving, Hence an automated solution is required.

Option of having schemaRegistry is good but its not in the option for current implementation.