Google Apps Script to convert exported Google Keep note titles to headers

Google Keep to Docs Headers

function boldTitlesToHeaders(headerSize) {
 // headerSize = 2;
  var headerStyle = p__getHeadingType(headerSize);
  var doc = DocumentApp.getActiveDocument();
  var body = doc.getBody();
  var numParagraphs = body.getNumChildren();
  
  for (var i = 0; i < numParagraphs; i++) {
    var element = body.getChild(i);

    if (element.getType() == DocumentApp.ElementType.PARAGRAPH) {
      var paragraph = element.asParagraph();
      var text = paragraph.getText();
      
      // Check each text element within the paragraph
      for (var j = 0; j < paragraph.getNumChildren(); j++) {
        var child = paragraph.getChild(j);
        if (child.getType() == DocumentApp.ElementType.TEXT) {
          var textElement = child.asText();
          if (textElement.isBold()) {
            p__changeNoteTitle(paragraph, headerStyle);
            break; // We've found bold text, so we don't need to check further.
          }
        }
      }
    }
  }
}

function p__getHeadingType(headerSize) {
  switch(headerSize) {
    case 1: return DocumentApp.ParagraphHeading.HEADING1;
    case 2: return DocumentApp.ParagraphHeading.HEADING2;
    case 3: return DocumentApp.ParagraphHeading.HEADING3;
    case 4: return DocumentApp.ParagraphHeading.HEADING4;
    case 5: return DocumentApp.ParagraphHeading.HEADING5;
    default: return DocumentApp.ParagraphHeading.HEADING4; 
  }
}


function p__changeNoteTitle(paragraph, headingStyle) {
  var text = paragraph.getText();
  
  // Insert a new Heading paragraph directly after the current paragraph
  var parent = paragraph.getParent();
  var index = parent.getChildIndex(paragraph);
  
  var newHeading = paragraph.copy().setHeading(headingStyle);
  parent.insertParagraph(index + 1, newHeading);
  
  // Remove the original paragraph
  parent.removeChild(paragraph);
}

Usage:

1. Open the Google Doc that was exported from Google Keep
2. Select Extensions / Apps Script
3. Paste the Gist code above into the project window
4. Uncomment out the //headerSize = 2; Set the headerSize to what you'd like from H1 to H5 using just the numeric value. 4 is a good choice.
5. Run the code directly on the current Doc by hitting the Run button (your Doc should now have headers on the left Docs outline)
6. You can make it a library and save the library to use on any Doc (https://developers.google.com/apps-script/guides/libraries) or just add the code to each Doc

Example:
Saved the code as a library with the name "KeepHeaders"

Use:
In any Doc then, add this code:

function myFunction() {
  KeepHeaders.boldTitlesToHeaders(3);
}