prevent verify-misspelling failing on releases

Removes pull request subjects from release notes and checks
the remainder of text.

Makefile

@@ -517,12 +517,16 @@ verify-gofmt:
 verify-packages: ${BINDATA_TARGETS}
 	hack/verify-packages.sh
 
+# check code and docs inplace, then find release notes, remove PR titles and run misspell against the remaining text
 .PHONY: verify-misspelling
 verify-misspelling:
 	@which misspell 2>/dev/null ; if [ $$? -eq 1 ]; then \
 		go get -u github.com/client9/misspell/cmd/misspell; \
 	fi
-	@find . -type f \( -name "*.go*" -o -name "*.md*" \) -a \( -not -path "./vendor/*" -not -path "./_vendor/*" \) | \
+	@mkdir -p .build/docs
+	@find . -type f \( -name "*.go*" -o -name "*.md*" \) -a -path "./docs/releases/*" -exec basename {} \; | \
+		xargs -I{} sh -c 'sed -e "/^\* .*github.com\/kubernetes\/kops\/pull/d" docs/releases/{} > .build/docs/$(basename {})'
+	@find . -type f \( -name "*.go*" -o -name "*.md*" \) -a \( -not -path "./vendor/*" -not -path "./_vendor/*" -not -path "./docs/releases/*" \) | \
 		sed -e /README-ES.md/d -e /node_modules/d | \
 		xargs misspell -error