Add INSTALL, fix README typo.

INSTALL

@@ -0,0 +1,14 @@
+Installation
+--------------------
+# Install libgcrypt first, e.g. via `brew install libgcrypt` on OS X or libgcrypt-dev on Linux
+# Generate the final build scripts
+./autogen.sh
+# Build the CLI and library
+./configure && make
+
+Troubleshooting
+--------------------
+If libgcrypt isn't found after install, set AM_PATH_LIBGCRYPT env var to libgcrypt path 
+prior to running autogen.sh. For example, on OS X with ver 1.7.6:
+
+export AM_PATH_LIBGCRYPT="/usr/local/Cellar/libgcrypt/1.7.6/lib"

Makefile.am

@@ -14,7 +14,7 @@ pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libbase58.pc
 
 dist_noinst_SCRIPTS = autogen.sh
-dist_doc_DATA = AUTHORS COPYING README
+dist_doc_DATA = AUTHORS COPYING INSTALL README
 
 if USE_TOOL
 bin_PROGRAMS = base58

README

@@ -50,7 +50,7 @@ return false. Otherwise, it returns true to indicate success.
 Encoding Base58Check
 --------------------
 
-Targetting base58check is done similarly to raw base58 encoding, but you must
+Targeting base58check is done similarly to raw base58 encoding, but you must
 also provide a version byte:
 	bool b58check_enc(char *b58c, size_t *b58c_sz, uint8_t ver,
 	                  const void *data, size_t datasz)