docs(man): implement manpage

- Implement `make man` to generate a manpage

- Change verb tense in `make` help text

Makefile

@@ -11,7 +11,9 @@ GO     := go
 GREP   := grep
 GZIP   := gzip --best
 LINT   := revive
+MAN    := man
 MKDIR  := mkdir -p
+PANDOC := pandoc
 RM     := rm
 SCC    := scc
 SED    := sed
@@ -32,16 +34,16 @@ releases :=                        \
 	$(dist_dir)/cheat-linux-arm7   \
 	$(dist_dir)/cheat-windows-amd64.exe
 
-## build: builds an executable for your architecture
+## build: build an executable for your architecture
 .PHONY: build
-build: $(dist_dir) clean vendor generate
+build: $(dist_dir) clean vendor generate man
 	$(GO) build $(BUILD_FLAGS) -o $(dist_dir)/cheat $(cmd_dir)
 
-## build-release: builds release executables
+## build-release: build release executables
 .PHONY: build-release
 build-release: $(releases)
 
-## ci: builds a "release" executable for the current architecture (used in ci)
+## ci: build a "release" executable for the current architecture (used in ci)
 .PHONY: ci
 ci: | setup prepare build
 
@@ -83,75 +85,81 @@ $(dist_dir):
 generate:
 	$(GO) generate $(cmd_dir)
 
-## install: builds and installs cheat on your PATH
+## install: build and install cheat on your PATH
 .PHONY: install
 install: build
 	$(GO) install $(BUILD_FLAGS) $(GOBIN) $(cmd_dir) 
 
-## clean: removes compiled executables
+## clean: remove compiled executables
 .PHONY: clean
 clean: $(dist_dir)
 	$(RM) -f $(dist_dir)/*
 
-## distclean: removes the tags file
+## distclean: remove the tags file
 .PHONY: distclean
 distclean:
 	$(RM) -f tags
 
-## setup: installs revive (linter) and scc (sloc tool)
+## setup: install revive (linter) and scc (sloc tool)
 .PHONY: setup
 setup:
 	GO111MODULE=off $(GO) get -u github.com/boyter/scc github.com/mgechev/revive
 
-## sloc: counts "semantic lines of code"
+## sloc: count "semantic lines of code"
 .PHONY: sloc
 sloc:
 	$(SCC) --exclude-dir=vendor
 
-## tags: builds a tags file
+## tags: build a tags file
 .PHONY: tags
 tags:
 	$(CTAGS) -R --exclude=vendor --languages=go
 
-## vendor: downloads, tidies, and verifies dependencies
+## man: build a man page
+# NB: pandoc may not be installed, so we're ignoring this error on failure
+.PHONY: man
+man:
+	-$(PANDOC) -s -t man doc/cheat.1.md -o doc/cheat.1
+
+## vendor: download, tidy, and verify dependencies
 .PHONY: vendor
 vendor:
 	$(GO) mod vendor && $(GO) mod tidy && $(GO) mod verify
 
-## fmt: runs go fmt
+## fmt: run go fmt
 .PHONY: fmt
 fmt:
 	$(GO) fmt ./...
 
-## lint: lints go source files
+## lint: lint go source files
 .PHONY: lint
 lint: vendor
 	$(LINT) -exclude vendor/... ./...
 
-## vet: vets go source files
+## vet: vet go source files
 .PHONY: vet
 vet:
 	$(GO) vet ./...
 
-## test: runs unit-tests
+## test: run unit-tests
 .PHONY: test
 test: 
 	$(GO) test ./...
 
-## coverage: generates a test coverage report
+## coverage: generate a test coverage report
 .PHONY: coverage
 coverage:
 	$(GO) test ./... -coverprofile=$(TMPDIR)/cheat-coverage.out && \
 	$(GO) tool cover -html=$(TMPDIR)/cheat-coverage.out
 
-## check: formats, lints, vets, vendors, and run unit-tests
+## check: format, lint, vet, vendor, and run unit-tests
 .PHONY: check
 check: | vendor fmt lint vet test
 
 .PHONY: prepare
 prepare: | $(dist_dir) clean generate vendor fmt lint vet test
 
-## help: displays this help text
+## help: display this help text
 .PHONY: help
 help:
 	@$(CAT) $(makefile) | \