site: Add Generated variable

This also removes the need for the feed Updated variable.

dir.go

@@ -204,7 +204,6 @@ func (d Dir) buildFeed(cfg *Site, feed Feed) ([]byte, error) {
 	type Feed struct {
 		Title     string
 		Permalink string
-		Updated   time.Time
 		Pages     []*Page
 	}
 
@@ -217,7 +216,6 @@ func (d Dir) buildFeed(cfg *Site, feed Feed) ([]byte, error) {
 	data := Feed{
 		Title:     feed.Title,
 		Permalink: d.Permalink,
-		Updated:   time.Now(),
 		Pages:     d.Pages,
 	}
 	if err := tmpl.Execute(&b, data); err != nil {

docs/kiln.1.scd

@@ -637,6 +637,8 @@ Site metadata contains the following data:
 :  The URLs of the site.
 |  Params
 :  Extra parameters specified in configuration.
+|  Generated
+:  Site generation time.
 
 To configure these variables, see *CONFIGURATION*.
 

site.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"text/template"
+	"time"
 
 	"github.com/pelletier/go-toml"
 )
@@ -15,6 +16,7 @@ type Site struct {
 	Tasks      []*Task           `toml:"tasks"`
 	Params     map[string]string `toml:"params"`
 	Permalinks map[string]string `toml:"permalinks"`
+	Generated  time.Time         `toml:"-"`
 	permalinks map[string]*template.Template
 	templates  Templates
 	root       *Dir
@@ -58,7 +60,9 @@ func LoadSite(config string) (*Site, error) {
 	}
 	defer f.Close()
 
-	site := &Site{}
+	site := &Site{
+		Generated: time.Now(),
+	}
 	if err := toml.NewDecoder(f).Decode(site); err != nil {
 		return nil, err
 	}

templates/_default/atom.xml

@@ -2,7 +2,7 @@
 <feed xmlns="http://www.w3.org/2005/Atom">
 <id>{{ index site.URLs 0 }}{{ .Permalink }}</id>
 <title>{{ .Title }}</title>
-<updated>{{ .Updated.Format "2006-01-02T15:04:05Z07:00" }}</updated>
+<updated>{{ site.Generated.Format "2006-01-02T15:04:05Z07:00" }}</updated>
 <link href="{{ index site.URLs 0 | safeURL }}{{ .Permalink }}" rel="alternate"/>
 {{ range .Pages }}<entry>
 	<id>{{ index site.URLs 0 }}{{ .Permalink }}</id>