[bugfix] Markdown formatting updates (#743)

* add minify dependency specifically for markdown

* rearrange markdown formatting

* update markdown tests

vendor/github.com/tdewolff/parse/v2/position.go

@@ -0,0 +1,95 @@
+package parse
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"unicode"
+)
+
+// Position returns the line and column number for a certain position in a file. It is useful for recovering the position in a file that caused an error.
+// It only treates \n, \r, and \r\n as newlines, which might be different from some languages also recognizing \f, \u2028, and \u2029 to be newlines.
+func Position(r io.Reader, offset int) (line, col int, context string) {
+	l := NewInput(r)
+	line = 1
+	for l.Pos() < offset {
+		c := l.Peek(0)
+		n := 1
+		newline := false
+		if c == '\n' {
+			newline = true
+		} else if c == '\r' {
+			if l.Peek(1) == '\n' {
+				newline = true
+				n = 2
+			} else {
+				newline = true
+			}
+		} else if c >= 0xC0 {
+			var r rune
+			if r, n = l.PeekRune(0); r == '\u2028' || r == '\u2029' {
+				newline = true
+			}
+		} else if c == 0 && l.Err() != nil {
+			break
+		}
+
+		if 1 < n && offset < l.Pos()+n {
+			break
+		}
+		l.Move(n)
+
+		if newline {
+			line++
+			offset -= l.Pos()
+			l.Skip()
+		}
+	}
+
+	col = len([]rune(string(l.Lexeme()))) + 1
+	context = positionContext(l, line, col)
+	return
+}
+
+func positionContext(l *Input, line, col int) (context string) {
+	for {
+		c := l.Peek(0)
+		if c == 0 && l.Err() != nil || c == '\n' || c == '\r' {
+			break
+		}
+		l.Move(1)
+	}
+	rs := []rune(string(l.Lexeme()))
+
+	// cut off front or rear of context to stay between 60 characters
+	limit := 60
+	offset := 20
+	ellipsisFront := ""
+	ellipsisRear := ""
+	if limit < len(rs) {
+		if col <= limit-offset {
+			ellipsisRear = "..."
+			rs = rs[:limit-3]
+		} else if col >= len(rs)-offset-3 {
+			ellipsisFront = "..."
+			col -= len(rs) - offset - offset - 7
+			rs = rs[len(rs)-offset-offset-4:]
+		} else {
+			ellipsisFront = "..."
+			ellipsisRear = "..."
+			rs = rs[col-offset-1 : col+offset]
+			col = offset + 4
+		}
+	}
+
+	// replace unprintable characters by a space
+	for i, r := range rs {
+		if !unicode.IsGraphic(r) {
+			rs[i] = '·'
+		}
+	}
+
+	context += fmt.Sprintf("%5d: %s%s%s\n", line, ellipsisFront, string(rs), ellipsisRear)
+	context += fmt.Sprintf("%s^", strings.Repeat(" ", 6+col))
+	return
+}