Add to & improve wording of `source` & add entry

sheets/source

@@ -1,6 +1,15 @@
-# This is a shell built-in available in Bash, but not in the Bourne Shell
-# (`sh`). The contents of FILE (assuming shell script) will be sourced into the
-# current session, allowing external use of its functions, variables, etc.
+# source
+# Execute commands from a file in the current shell
+
+# This is a shell built-in, available within most if not all shells. However, -
+# it may only be available as `.` in some older shells, such as Bourne shell.
+# Its first argument is a file, with all proceeding arguments being parameters
+# to the aforementioned file.
+
+# Run shell code residing within FILE as though you'd entered it in yourself.
 source FILE
-# The above can be written in short-hand, for the same effect:
+# The above can be written in short-hand, for the same effect, shell allowing.
 . FILE
+
+#  Source FILE with the given arguments to said file.
+source FILE Argument_1 Argument_2 Argument_3 ...