document: Move <file-document> code to a new (tissue file-document).

* tissue/document.scm: Do not import (srfi srfi-171).
(<file-document>, document-type, document-id-term, document-text,
document-term-generator, print, document->sxml,
read-gemtext-document): Move to (tissue file-document).
(document-id-term, document-text, print, document->sxml): Declare as
generic functions.
* tissue/file-document.scm: New file.
* tissue/issue.scm, bin/tissue: Import (tissue file-document).

1 files changed, 1 insertions, 0 deletions

diff --git a/bin/tissue b/bin/tissue
index 6e82b5b..2170501 100755
--- a/bin/tissue
+++ b/bin/tissue
@@ -39,6 +39,7 @@ exec guile --no-auto-compile -s "$0" "$@"
         (xapian wrap)
         (xapian xapian)
         (tissue commit)
+        (tissue file-document)
         (tissue document)
         (tissue git)
         (tissue issue)