libk  Check-in [2aab529520]

Modified libk.md from [602b81e913] to [ff7e1c7779].

   163    163   to build libk, you must invoke `build.sh` with the proper parameters. at minimum you must set the following environment variables:
   164    164   
   165    165    * `os={atom}` - an atom representing the operating system you are building libk for
   166    166    * `arch={atom}` - an atom representing the processor architecture you are building libk for
   167    167    * `bits={atom}` - if your processor has multiple variants with different word lengths (such as x86-32 vs. x86-64), specify the word length in this variable; otherwise, leave it unset.
   168    168   
   169    169   further optional variables may be set to control the build process and determine what targets it produces.
          170  +
   170    171    * `library=static {static|shared|both}` - this variable controls whether the build process will produce `libk.a`, `libk.so`, or both.
   171    172    * `to=out {path}` - an alternate path to store build artifacts in
   172    173    * `gen=gen {path}` - an alternate path to store generated source in
   173    174    * `cc=<autodetect> {executable}` - the compiler to compile C sources with
   174    175    * `m4=<autodetect> {executable}` - the m4 binary to compile the macro sources with
   175    176    * `asm=<autodetect> {executable}` - the assembler to assemble the assembly listings with. it must take Intel-syntax input and handle nasm-style macros. only `yasm` and `nasm` are likely to be viable.
   176    177    * `doc=yes {yes|no}` - whether to typeset the documentation (very slow with all three formats set to "yes")