deploytool: Add README.md, migrate docs to it.

deploytool/cmd/title.go

-// Copyright 2016 The LUCI Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-package main
-
-import (
-        "path/filepath"
-        "unicode"
-
-        "github.com/luci/luci-go/common/errors"
-)
-
-type title string
-
-func (t title) validate() error {
-        if len(t) == 0 {
-                return errors.New("cannot be empty")
-        }
-
-        idx := 0
-        for _, r := range t {
-                if !(unicode.IsLetter(r) || unicode.IsNumber(r) || r == '-') {
-                        return errors.Reason("character at %(pos)d (%(char)c) is not permitted in a title").
-                                D("pos", idx).D("char", r).Err()
-                }
-                idx++
-        }
-        return nil
-}
-
-// titleFromConfigPath returns the title of a configuration item identified by
-// the specified configuration file.
-//
-// If the file was not a valid config path, or the title was not valid, an error
-// will be returned.
-func titleFromConfigPath(path string) (title, error) {
-        path = filepath.Base(path)
-        if filepath.Ext(path) == configExt {
-                t := title(path[:len(path)-len(configExt)])
-                if err := t.validate(); err != nil {
-                        return "", err
-                }
-                return t, nil
-        }
-        return "", errors.Reason("missing config extension [" + configExt + "]").Err()
-}