updated readme

README.md

@@ -20,6 +20,8 @@ These are:
 
  - CC      -> C compiler
  - CFLAGS  -> compilation flags
+ - AR      -> archiver
+ - ARFLAGS -> archiver flags
  - LDLIBS  -> linker libraries
  - LDFLAGS -> linker flags
  - TARGET  -> name of final executable/library
@@ -28,6 +30,8 @@ These are:
  - INCS   -> place for `-I` compiler flags to specify include directories. (must
              be placed in this variable, not in CFLAGS or elsewhere)
 
+ (CC, LDLIBS, and LDFLAGS are also used for dynamic library creation.)
+
 It is therefore recommended that you set these at the beginning of your
 makefile, unless you want to use the `make` defaults.
 
@@ -62,8 +66,9 @@ Options:
   -p, --pretty               Replace default make output with nice build messages (colors!)
   -c, --clean                Generate a 'clean' rule that removes all build files
   -r, --run                  Generate a 'run' rule that allows you run the executable with 'make run'
-  -l, --library              Configure build rule to create a library rather than an executable (NYI)
-  -m, --makefile <MAKEFILE>  Path to makefile [default: ./Makefile]
+  -s, --static-library       Configure to build a statically linked library
+  -d, --dynamic-library      Configure to build a dynamically linked library
+  -m, --makefile <MAKEFILE>  Path to makefile [default: Makefile]
   -h, --help                 Print help
 ```
 
@@ -76,6 +81,8 @@ object files (that's what `mgen` is for). You can keep any other, more complex
 rules that depend on these things, though. Then, run `mgen` and `make` and you
 are good to go.
 
+Note that you can only choose one of `-r`, `-s` or `-d` for obvious reasons.
+
 ## Build Instructions
 
 Build: `cargo build --release`
@@ -86,8 +93,6 @@ Uninstall (needs root): `sh uninstall.sh`
 
 ## Todo
 
-- Add functionality to generate rules to build a library, as opposed to an
-  executable.
 - Add exclude directory(ies) from search
 - Eventually: write man page.
 - Maybe: figure out a way to only have the user run `mgen` once, then the