docs: add example code

Author: ww24

example/go.mod

@@ -0,0 +1,42 @@
+module github.com/go-oss/scheduler/example
+
+go 1.17
+
+replace github.com/go-oss/scheduler => ../
+
+require (
+	cloud.google.com/go/cloudtasks v1.0.0
+	github.com/go-oss/scheduler v0.0.0-00010101000000-000000000000
+)
+
+require (
+	cloud.google.com/go v0.97.0 // indirect
+	github.com/BurntSushi/toml v0.3.1 // indirect
+	github.com/census-instrumentation/opencensus-proto v0.2.1 // indirect
+	github.com/cespare/xxhash v1.1.0 // indirect
+	github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403 // indirect
+	github.com/cncf/xds/go v0.0.0-20210312221358-fbca930ec8ed // indirect
+	github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0 // indirect
+	github.com/envoyproxy/protoc-gen-validate v0.1.0 // indirect
+	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/go-cmp v0.5.6 // indirect
+	github.com/googleapis/gax-go v1.0.3 // indirect
+	github.com/googleapis/gax-go/v2 v2.1.1 // indirect
+	go.opencensus.io v0.23.0 // indirect
+	golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6 // indirect
+	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616 // indirect
+	golang.org/x/mod v0.4.2 // indirect
+	golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420 // indirect
+	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8 // indirect
+	golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359 // indirect
+	golang.org/x/text v0.3.6 // indirect
+	golang.org/x/tools v0.1.5 // indirect
+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
+	google.golang.org/api v0.60.0 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20211021150943-2b146023228c // indirect
+	google.golang.org/grpc v1.40.0 // indirect
+	google.golang.org/protobuf v1.27.1 // indirect
+	honnef.co/go/tools v0.0.1-2020.1.4 // indirect
+)