2014-01-22: bootstrap: finish the command example with `

bootstrap: finish the command example with `

diff --git a/bootstrap.sh b/bootstrap.sh
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -20,4 +20,4 @@ guile wisp.scm ${srcdir}/wisp-reader.w 2
     && echo ...precompiling the spec file... \
     && guile -L . -s language/wisp/spec.scm \
     && echo ...succeeded \
-    && echo 'to use wisp at the REPL, run `guile -L . --language=wisp'
+    && echo 'to use wisp at the REPL, run `guile -L . --language=wisp`'