feat(npm): add fallback 3rd-party completion loader

https://github.com/ohmybash/oh-my-bash/blob/b4a2264496e14f883101ec15e35607b2e7386acc/completions/npm.completion.sh

Author: akinomyoga

completions/.gitignore

@@ -196,6 +196,7 @@
 /neomutt
 /_nfpm
 /_nomad
+/_npm
 /_oc
 /_okteto
 /_op

completions/Makefile.am

@@ -736,6 +736,7 @@ CLEANFILES = \
 	neomutt \
 	_nfpm \
 	_nomad \
+	_npm \
 	_oc \
 	_okteto \
 	_op \
@@ -966,7 +967,7 @@ symlinks: $(DATA)
 	$(ss) freeciv-server \
 		civserver
 	$(ss) _gaiacli \
-		_gaiad _tendermint
+		_gaiad _npm _tendermint
 	$(ss) gcc \
 		c++ cc f77 f95 g++ g++-5 g++-6 g++-7 g++-8 g77 g95 gcc-5 \
 		gcc-6 gcc-7 gcc-8 gccgo gccgo-5 gccgo-6 gccgo-7 gccgo-8 gcj \