[Tex/LaTex] footnote goes over margin

Question

The second line of the footnote goes over the left margin.

How can I achieve that the second line is in a line with the first line?

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}

@incollection{incollection,
    author       = {Peter Farindon}, 
    title        = {The title of the work},
    booktitle    = {The title of the book},
    publisher    = {The name of the publisher},
    year         = 1993,
    pages     ={10},
}


\end{filecontents}

\documentclass{article}
\usepackage[style=verbose]{biblatex}
\usepackage[ngerman]{babel}
\usepackage{csquotes}


\addbibresource{\jobname.bib}
\begin{document}
    Let's cite!  \footcite{incollection} 
    \printbibliography
\end{document}

Answer 1

You can define the layout of the footnote with the following code added to the preamble:

\makeatletter
\renewcommand{\@makefntext}[1]{%
  \setlength{\parindent}{0pt}%
  \begin{list}{}{%
    \setlength{\labelwidth}{1.5em}% <===================================
    \setlength{\leftmargin}{\labelwidth}%
    \setlength{\labelsep}{3pt}%
    \setlength{\itemsep}{0pt}%
    \setlength{\parsep}{0pt}%
    \setlength{\topsep}{0pt}%
%   \setlength{\rightmargin}{0.2\textwidth}%
    \footnotesize}%
  \item[\@makefnmark\hfil]#1%
  \end{list}%
}
\makeatother

The command \setlength{\labelwidth}{1.5em} defines the length given to the foornote number you can change for your needs ...

The complete code

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}

@incollection{incollection,
    author       = {Peter Farindon}, 
    title        = {The title of the work},
    booktitle    = {The title of the book},
    publisher    = {The name of the publisher},
    year         = 1993,
    pages     ={10},
}


\end{filecontents}

\documentclass{article}
\usepackage[style=verbose]{biblatex}
\usepackage[ngerman]{babel}
\usepackage{csquotes}

\makeatletter
\renewcommand{\@makefntext}[1]{%
  \setlength{\parindent}{0pt}%
  \begin{list}{}{%
    \setlength{\labelwidth}{1.5em}% <===================================
    \setlength{\leftmargin}{\labelwidth}%
    \setlength{\labelsep}{3pt}%
    \setlength{\itemsep}{0pt}%
    \setlength{\parsep}{0pt}%
    \setlength{\topsep}{0pt}%
%   \setlength{\rightmargin}{0.2\textwidth}%
    \footnotesize}%
  \item[\@makefnmark\hfil]#1%
  \end{list}%
}
\makeatother


\addbibresource{\jobname.bib}
\begin{document}
    Let's cite!  \footcite{incollection} 
    \printbibliography
\end{document}

gives you the result:

If you do not want the second line indentend on the left change \setlength{\leftmargin}{\labelwidth} for example to \setlength{\leftmargin}{0pt} ...

Because you are writing in German please consider to use normal footnote numbers (have a look into the German Duden). To get that please add the line

\renewcommand{\@makefnmark}{\hbox{\normalfont\@thefnmark}}

after \makeatletter ...

Then you get with the complete code

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}

@incollection{incollection,
    author       = {Peter Farindon}, 
    title        = {The title of the work},
    booktitle    = {The title of the book},
    publisher    = {The name of the publisher},
    year         = 1993,
    pages     ={10},
}


\end{filecontents}

\documentclass{article}
\usepackage[style=verbose]{biblatex}
\usepackage[ngerman]{babel}
\usepackage{csquotes}

\makeatletter
\renewcommand{\@makefnmark}{\hbox{\normalfont\@thefnmark}} % <==========
\renewcommand{\@makefntext}[1]{%
  \setlength{\parindent}{0pt}%
  \begin{list}{}{%
    \setlength{\labelwidth}{1.5em}% <===================================
    \setlength{\leftmargin}{\labelwidth}%
    \setlength{\labelsep}{3pt}%
    \setlength{\itemsep}{0pt}%
    \setlength{\parsep}{0pt}%
    \setlength{\topsep}{0pt}%
%   \setlength{\rightmargin}{0.2\textwidth}%
    \footnotesize}%
  \item[\@makefnmark\hfil]#1%
  \end{list}%
}
\makeatother


\addbibresource{\jobname.bib}
\begin{document}
    Let's cite!  \footcite{incollection} 
    \printbibliography
\end{document}

the result