Example in section "Printing stanzas at the end in multiple columns" doesn't align text baselines precisely

[MártonKároly]

Notation Reference 2.1.3. example, slightly modified

The 5th verse is printed slightly BELOW the 3rd! (the bottom of the 
letter 'g' is below the bottom of the letter 'l' and distances are 
measured from the bottom of the letters and not from the baselines)

Text boxes should be introduced to handle this problem because it's not 
always possible to measure all distances from the text baselines.

\markup {
  \fill-line {
    \hspace #0.1 % moves the column off the left margin;
     % can be removed if space on the page is tight
     \column {
      \line { \bold "2."
        \column {
          "This is verse two."
          "It has two lines."
        }
      }
      \combine \null \vspace #0.1 % adds vertical spacing between verses
      \line { \bold "3."
        \column {
          "This is verse three."
          "It has two lines."
        }
      }
    }
    \hspace #0.1 % adds horizontal spacing between columns;
    \column {
      \line { \bold "4."
        \column {
          "This is verse four."
          "gggggggggggggggggg"
        }
      }
      \combine \null \vspace #0.1 % adds vertical spacing between verses
      \line { \bold "5."
        \column {
          "This is verse five."
          "It has two lines."
        }
      }
    }
  \hspace #0.1 % gives some extra space on the right margin;
  % can be removed if page space is tight
  }
}