Add data-epub-type to ToC & Index (#1888)

* Add `data-epub-type` to ToC & Index

Added to autogenerated ToC, and to index created during
autogeneration by `/i...i/` markup.

Fixes #1885

* Fix tests

Author: windymilla

src/guiguts/html_convert.py

@@ -695,7 +695,7 @@ def maybe_close_chapter_div(chapter_div_open: bool, next_step: int) -> int:
             maintext().replace(
                 line_start,
                 line_end,
-                '<nav>\n<ul class="index">',
+                '<nav data-epub-type="index">\n<ul class="index">',
             )
             next_step += 1
             reset_ibs_dict()
@@ -975,7 +975,7 @@ def maybe_close_chapter_div(chapter_div_open: bool, next_step: int) -> int:
         maintext().insert(
             contents_start,
             "\n<!-- Autogenerated TOC. Modify or delete as required. -->\n"
-            f"<nav>\n<p>\n{auto_toc}</p>\n</nav>\n"
+            f'<nav data-epub-type="toc">\n<p>\n{auto_toc}</p>\n</nav>\n'
             "<!-- End Autogenerated TOC. -->\n\n",
         )
 

tests/expected/htmlconvert1.txt

@@ -255,7 +255,7 @@ img.w100 {width: 100%;}
 
 
 <!-- Autogenerated TOC. Modify or delete as required. -->
-<nav>
+<nav data-epub-type="toc">
 <p>
 <a href="#NOTES_FROM_CALAIS_BASE">NOTES FROM CALAIS BASE ——-File: 002.png————————————————————————————- [Blank Page] ——-File: px003a.png———————————————————————————- /s p003a</a><br>
 <a href="#TRAINING_IN_FRANCE">TRAINING IN FRANCE</a><br>

tests/expected/htmlconvert2.txt

@@ -335,7 +335,7 @@ CHERRY-BLOSSOMS
 </div>
 
 <!-- Autogenerated TOC. Modify or delete as required. -->
-<nav>
+<nav data-epub-type="toc">
 <p>
 <a href="#Many_have_been_before_me_and_the_theme">Many have been before me, and the theme of this volume can hardly be called new, for Japan has been viewed from every side and through all kinds of eyes. This, however, has not deterred me from jotting down a few observations and experiences of my own, hoping that in them my readers may feel some rays of the Orient sunshine and beauty. I desire to thank Mr. Burton J. Hendrick for the kind and sympathetic aid given upon the manuscript.</a><br>
 <a href="#CONTENTS">CONTENTS.</a><br>