Update docs to reflect actual implementations

Author: morr0ne

docs/cat.txt

@@ -1,2 +1,7 @@
-Usage: cat [OPTION]... [FILE]...
+Usage: cat [FILE]...
 Concatenate FILE(s) to standard output.
+
+      --help     display this help and exit
+      --version  output version information and exit
+
+With no FILE, or when FILE is -, read standard input.

docs/false.txt

@@ -1 +1,9 @@
+Usage: false [ignored command line arguments]
 Exit with a status code indicating failure.
+
+      --help     display this help and exit
+      --version  output version information and exit
+
+NOTE: your shell may have its own version of false, which usually supersedes
+the version described here.  Please refer to your shell's documentation
+for details about the options it supports.

docs/mkdir.txt

@@ -1,2 +1,7 @@
 Usage: mkdir [OPTION]... DIRECTORY...
 Create the DIRECTORY(ies), if they do not already exist.
+
+      --help     display this help and exit
+      --version  output version information and exit
+
+Each DIRECTORY is created with mode 0777 modified by the umask.

docs/pwd.txt

@@ -1,2 +1,9 @@
 Usage: pwd [OPTION]...
 Print the full filename of the current working directory.
+
+  -L, --logical   use PWD from environment, even if it contains symlinks
+  -P, --physical  avoid all symlinks (default)
+      --help      display this help and exit
+      --version   output version information and exit
+
+If no option is specified, -P is assumed.

docs/true.txt

@@ -1 +1,9 @@
+Usage: true [ignored command line arguments]
 Exit with a status code indicating success.
+
+      --help     display this help and exit
+      --version  output version information and exit
+
+NOTE: your shell may have its own version of true, which usually supersedes
+the version described here.  Please refer to your shell's documentation
+for details about the options it supports.

docs/wc.txt

@@ -1,4 +1,11 @@
 Usage: wc [OPTION]... [FILE]...
-Print newline, word, and byte counts for each FILE, and a total line if
-more than one FILE is specified.  A word is a nonempty sequence of non white
-space delimited by white space characters or by start or end of input.
+Print newline, word, and byte counts for each FILE.  A word is a nonempty 
+sequence of non white space delimited by white space characters or by start 
+or end of input.
+
+  -c, --bytes    print the byte counts
+  -m, --chars    print the character counts
+  -l, --lines    print the newline counts
+  -w, --words    print the word counts
+      --help     display this help and exit
+      --version  output version information and exit

docs/yes.txt

@@ -1 +1,5 @@
 Usage: yes [STRING]...
+Repeatedly output a line with all specified STRING(s), or 'y'.
+
+      --help     display this help and exit
+      --version  output version information and exit