Implement multiplication

TODO

@@ -1,4 +1,23 @@
-# Completion
+# Compiler
+
+- Separate headers and sources for the compiler, shell and tests.
+- Make writing ELF independent from the code generation.
+- Argument parsing.
+- Whitespaces are checked twice, in the source class and by lexing.
+- Replace pointer and length with vectors and strings.
+- Choose one name for runner.cpp and tester.hpp.
+- Move argument handling into the cl module.
+- Catch exceptions thrown by the argument parser and print them normally.
+- cmake clean target.
+- Division.
+- Expressions contain one or more terms. Currently it parses another expression on the right side.
+- Multiple factors.
+
+# Shell
+- Persist the history.
+- Replace hard coded ANSI codes with constants or functions.
+
+## Completion
 
 - Configure fzf to show only the current directory files
 - Support multiple selections for insertion in fzf.
@@ -7,17 +26,12 @@
 - Home directory expansion.
 - Show files in the PATH if starting at the beginning of the prompt
 
-# Appearance
+## Appearance
 
 - Add a bar with additional information under the prompt (edit_bar), like the hostname.
 - Show current time in the prompt.
 
-# Input
+## Input
 
 - DEL handling.
 - Starting long running process and killing it with Ctrl-C kills the shell.
-
-# Other
-
-- Persist the history.
-- Replace hard coded ANSI codes with constants or functions.