Start writer module documentation

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@@ -4104,6 +4104,19 @@ Sets the preconditioner type.
 
 Sets verbosity mode to ~true~ or ~false~ for linear solvers.
 
+*** The ~writer~ module
+
+This module provides functionalities to numerical results to files for
+post processing.
+
+It provides the following functions and types.
+#+NAME: get-module-info-writer
+#+BEGIN_SRC pugs :exports both :results output
+  cout << getModuleInfo("writer") << "\n";
+#+END_SRC
+#+RESULTS: get-module-info-writer
+
+
 [fn:pugs-def] ~pugs~: Parallel Unstructured Grid Solvers
 [fn:MPI-def] ~MPI~: Message Passing Interface
 [fn:DSL-def] ~DSL~: Domain Specific Language~