write headings for command line arguments

Author: steveklabnik

src/doc/rustc/src/SUMMARY.md

@@ -1,7 +1,7 @@
 # The Rustc Book
 
 - [What is rustc?](what-is-rustc.md)
-- [Command-line arguments](command-line-arguments/index.md)
+- [Command-line arguments](command-line-arguments.md)
 - [Lints](lints/index.md)
     - [Lint levels](lints/levels.md)
     - [Lint Groups](lints/groups.md)

src/doc/rustc/src/command-line-arguments.md

@@ -0,0 +1,57 @@
+# Command-line arguments
+
+Here's a list of command-line arguments to `rustc` and what they do.
+
+## `-h`/`--help`: get help
+
+## `--cfg`: configure the compilation environment
+
+## `-L`: add a directory to the library search path.
+
+## `-l`: link the generated crate to a native library
+
+## `--crate-type`: a list of types of crates for the compiler to emit
+
+## `--crate-name`: specify the name of the crate being built
+
+## `--emit`: emit output other than a crate
+
+## `--print`: print compiler information
+
+## `-g`: include debug information
+
+## `-O`: optimize your code
+
+## `-o`: filename of the output
+
+## `--out-dir`: directory to write the output in
+
+## `--explain`: provide a detailed explanation of an error message
+
+## `--test`: build a test harness
+
+## `--target`: select a target triple to build
+
+## `-W`: set lint warnings
+
+## `-A`: set lint allowed
+
+## `-D`: set lint denied
+
+## `-F`: set lint forbidden
+
+## `--cap-lints`: set the most restrictive lint level
+
+## `-C`/`--codegen`: code generation options
+
+## `-V`/`--verision`: print a version
+
+## `-v`/`--verbose`: use verbose output
+
+## `--extern`: specify where an external library is located
+
+## `--sysroot`: Override the system root
+
+## `--error-format`: control how errors are produced
+
+## `--color`: configur coloring of output