Document initial value of "cycle list name"

cycle list name is initialized with color, which is not documented. https://github.com/pgf-tikz/pgfplots/blob/324e29dbdf7cd21dccaff201e35ffdb0558c43c0/tex/generic/pgfplots/pgfplots.code.tex#L2454

Proposed change (which can be quickly formed to a PR once Christian Feuersaenger is back):

diff --git a/doc/latex/pgfplots/pgfplots.reference.markers-meta.tex b/doc/latex/pgfplots/pgfplots.reference.markers-meta.tex
index cd3596af..0c53110c 100644
--- a/doc/latex/pgfplots/pgfplots.reference.markers-meta.tex
+++ b/doc/latex/pgfplots/pgfplots.reference.markers-meta.tex
@@ -2527,7 +2527,7 @@ target pos={10,100,200,500,1000,1100,1200,1500,2000,2895}
 \subsection{Cycle Lists -- Options Controlling Line Styles}
 \label{sec:cycle:list}

-\begin{pgfplotskeylist}{cycle list=\marg{list},cycle list name=\marg{name}}
+\begin{pgfplotskeylist}{cycle list=\marg{list},cycle list name=\marg{name} (initially |color|)}
     Allows to specify a list of plot specifications which will be used for each
     \hbox{|\addplot|} command without explicit plot specification. Thus, the
     currently active |cycle list| will be used if you write either

Why and how this change would help

Next entry of currently used cycle list is

applied when \addplot with no optional argument or \addplot+ is used,
but both ignored and skipped when \addplot[...] is used,

which might confuse users about why \begin{axis}[samples=10] \addplot ...; \end{axis} and \begin{axis} \addplot[samples=10] ...; \end{axis} produce different plots. It actually confused me when answering this question.

With initial value of cycle list name documented, it at least helps careful users who are willing to read the doc. It will help more users if the differences between \addplot and \addplot[] are documented more explicitly.

pgf-tikz / pgfplots

Document initial value of "cycle list name" #371

Why and how this change would help