internal/godoc/dochtml: move identifers to template_*.go files

Identifiers are moved from legacy_*.go to template_*.go files, to make
it clear that these are being used by the new templates.

Change-Id: I533ba06357ac06d62b89703a04253f76a10974c8
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/260731
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/internal/godoc/dochtml/legacy_body.go b/internal/godoc/dochtml/legacy_body.go
index 3c8e799..4d5a9e9 100644
--- a/internal/godoc/dochtml/legacy_body.go
+++ b/internal/godoc/dochtml/legacy_body.go
@@ -4,11 +4,6 @@
 
 package dochtml
 
-const (
-	IdentifierBodyStart = `<div class="Documentation-content js-docContent">`
-	IdentifierBodyEnd   = `</div>`
-)
-
 const legacyTmplBody = `
 
 ` + IdentifierBodyStart + ` {{/* Documentation content container */}}
diff --git a/internal/godoc/dochtml/legacy_sidenav.go b/internal/godoc/dochtml/legacy_sidenav.go
index 7528640..642fce8 100644
--- a/internal/godoc/dochtml/legacy_sidenav.go
+++ b/internal/godoc/dochtml/legacy_sidenav.go
@@ -4,12 +4,6 @@
 
 package dochtml
 
-const (
-	IdentifierSidenavStart       = `<nav class="DocNav js-sideNav">`
-	IdentifierSidenavMobileStart = `<nav class="DocNavMobile js-mobileNav">`
-	IdentifierSidenavEnd         = `</nav>`
-)
-
 const legacyTmplSidenav = `
 {{if or .Doc .Consts .Vars .Funcs .Types .Examples.List}}
 	` + IdentifierSidenavStart + `
diff --git a/internal/godoc/dochtml/template_body.go b/internal/godoc/dochtml/template_body.go
index fb1b545..e1ecf81 100644
--- a/internal/godoc/dochtml/template_body.go
+++ b/internal/godoc/dochtml/template_body.go
@@ -4,6 +4,11 @@
 
 package dochtml
 
+const (
+	IdentifierBodyStart = `<div class="Documentation-content js-docContent">`
+	IdentifierBodyEnd   = `</div>`
+)
+
 const tmplBody = `
 
 ` + IdentifierBodyStart + ` {{/* Documentation content container */}}
diff --git a/internal/godoc/dochtml/template_sidenav.go b/internal/godoc/dochtml/template_sidenav.go
index e02226c..b2e1c78 100644
--- a/internal/godoc/dochtml/template_sidenav.go
+++ b/internal/godoc/dochtml/template_sidenav.go
@@ -4,6 +4,12 @@
 
 package dochtml
 
+const (
+	IdentifierSidenavStart       = `<nav class="DocNav js-sideNav">`
+	IdentifierSidenavMobileStart = `<nav class="DocNavMobile js-mobileNav">`
+	IdentifierSidenavEnd         = `</nav>`
+)
+
 const tmplSidenav = `
 {{if or .Doc .Consts .Vars .Funcs .Types}}
 	` + IdentifierSidenavStart + `