Store a Stucture changes of Dataset Using Git

I'm trying to store and track the huge and frequently changing structure of Power BI Dataset (not data) using Git.

Right now it's a text or .MD formatted document where all Power Query queries (manually copy-pasted one by one) are stored. All measures also are imported using DAX Studio and written at the end.

Briefly, it looks like this:

* Custom Functions
    * ExtractJsonFileContent
      let
          Source = (fileContent) =>
      let
      Source = Json.Document(fileContent)
      in
      Source
      in
          Source
    * Countries
      let
          Source = Json.Document(DS{[Name="lookups"]}[Content]{[Name="Countries.json"]}[Content],65001),
          #"Converted to Table" = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
---
          #"Sorted Rows" = Table.Sort(#"Changed Type",{{"Country", Order.Ascending}}),
          #"Added Index" = Table.AddIndexColumn(#"Sorted Rows", "heapCountryId", 1, 1, Int64.Type)
      in
          #"Added Index"    

DEFINE 
---- MODEL MEASURES BEGIN ----

MEASURE 'Some Table'[Fail Rate_Int] = 
    DIVIDE(
        [Total Failed Tickets_Int],
        [Total Created Tickets_Int]
        )
MEASURE 'Some Table'[Success Rate] = 1 - [Fail Rate_Int]
---- MODEL MEASURES END ----

Maybe there is a more effective way to store these structures?

And one more question: How to store the relations between tables and measures?