Fix links, instructions, update cheatsheet

Author: José Valim

cheatsheets/README.md

@@ -4,11 +4,11 @@ references, also called cheat sheets.
 
 To produce a .pdf starting from the .tex source, you need `tex`,
 and more specifically [LaTeX](https://www.latex-project.org/get/).
-The BasicTex variant is enough for the purpose of these sheets.
 
-If you do not manage to compile the source into a pdf, or if you
-manage only after taking additional steps, not mentioned here,
-please add the steps in this description.
+The BasicTex variant can be used as long as the following packages
+are available:
+
+    $ tlmgr install courier framed charter enumitem ec helvetica
 
 To compile a tex file EQUIS.tex into its corresponding EQUIS.pdf:
 

cheatsheets/gen-server.pdf

@@ -100,7 +100,7 @@
 \section*{GenServer - a cheat sheet}
 \begin{itemize}
   \setlength\itemsep{0em}
-\item[---] last version: \verb|https://elixir-lang.org/getting-started/mix-otp/cheat-sheet.pdf|
+\item[---] last version: \verb|https://elixir-lang.org/cheatsheets/gen-server.pdf|
 \item[---] reference: \verb|https://hexdocs.pm/elixir/GenServer.html|
 \end{itemize}
 \begin{comment}
@@ -109,8 +109,6 @@ \section*{GenServer - a cheat sheet}
   based on a work by Benjamin Tan Wei Hao,
   rewritten as a tex/tikz document by Mario Frasca,
   with José Valim validating the content.
-
-  TODO: add yourself to the authors if you think so.
 \end{comment}
 
 \begin{parchment}[initialization: .start $\rightarrow$ \bf\texttt{init/1}]
@@ -162,22 +160,11 @@ \section*{GenServer - a cheat sheet}
         (result.north west)+(0,-38pt) -- ($ (result.north east)+(0,-38pt) $);
 
 \path (result.south east)+(3em,0) node (reason) [immediate,anchor=south west,fill=green!30!yellow!18!white] {
-    \vspace*{-\baselineskip}
-\begin{verbatim}
-:normal
-:shutdown
-{:shutdown, _}
-_
-\end{verbatim}
+One of \verb|:normal|, \verb|:shutdown|, \verb|{:shutdown, _}|, or any other value. See the footnote for a link to the complete reference.
 };
 \path (reason.north west)+(-2pt,0) node [left-title,fill=green!25] {\rotatebox{90}{\^{}reason = }};
 \path (reason.north west)+(0,2pt) node [top-title,anchor=south west,fill=green!25] {applies globally};
 
-\path (reason.north west)+(0,2em) node (explain) [explain,anchor=south west] {
-$\bullet$ \texttt{:normal} doesn't log, doesn't break links $\bullet$ \texttt{:shutdown}, \texttt{\{:shutdown, \_\}} doesn't log, breaks links $\bullet$  anything else logs, breaks links.
-};
-  \path (explain.north west)+(-2pt,0) node [left-title,fill=white] {\rotatebox{90}{stop reasons}};
-
   \draw[->,draw=blue!50!black,dashed,thick,anchor=north west] (-7.3em,-3.3em) .. controls (-7em,-7em) and (-22.45em,-1em) .. (-22.45em,-5.5em) -- (-22.45em,-6.9em);
 
 \end{tikzpicture}
@@ -396,12 +383,6 @@ \section*{GenServer - a cheat sheet}
 
   \path (result.north west)+(-2pt,0) node [left-title,fill=green!25] {\rotatebox{90}{\^{}result =}};
 
-  \path (result.south east)+(3em,0) node (explain) [explain,anchor=south west] {
-the reasons (\verb|:normal|, \verb|:shutdown|, \verb|{:shutdown, _}|) expected from a well behaved \verb|GenServer| are not defined by \verb|GenServer|, but by either Erlang (\verb|:normal|) or the \verb|Supervisor| module.    
-};
-
-  \path (explain.north west)+(-2pt,0) node [left-title,fill=white] {\rotatebox{90}{explain reason}};
-
   \draw[color=blue!10!yellow!5,draw=blue!25!yellow,dashed]
         (result.north west)+(0,-38pt) -- ($ (result.north east)+(0,-38pt) $);
 
@@ -411,6 +392,7 @@ \section*{GenServer - a cheat sheet}
   \vspace*{-\baselineskip}
   \begin{itemize}
     \setlength\itemsep{0em}
+  \item[---] More on exit reasons: \verb|https://hexdocs.pm/elixir/Supervisor.html#module-exit-reasons-and-restarts|
   \item[---] use \verb|@impl true| before each definition to guarantee it matches the equivalent \verb|GenServer| callback.
   \item[---] callbacks not listed here are: \verb|code_change/3| and \verb|format_status/2|.
   \item[---] source: \verb|https://github.com/elixir-lang/elixir-lang.github.com|

cheatsheets/gen-server.tex

@@ -322,7 +322,7 @@ So far we have used three callbacks: `handle_call/3`, `handle_cast/2` and `handl
 
 Since any message, including the ones sent via `send/2`, go to `handle_info/2`, there is a chance unexpected messages will arrive to the server. Therefore, if we don't define the catch-all clause, those messages could cause our registry to crash, because no clause would match. We don't need to worry about such cases for `handle_call/3` and `handle_cast/2` though. Calls and casts are only done via the `GenServer` API, so an unknown message is quite likely a developer mistake.
 
-To help developers remember the differences between call, cast and info, the supported return values and more, we have a tiny [GenServer cheat sheet](https://raw.githubusercontent.com/elixir-lang/elixir-lang.github.com/master/cheatsheets/gen-server.pdf), and it comes with `tex`/`tikz` source.
+To help developers remember the differences between call, cast and info, the supported return values and more, we have a tiny [GenServer cheat sheet](/cheatsheets/gen-server.pdf), and it comes with `tex`/`tikz` source.
 
 ## Monitors or links?