edits made according to bookdown repo

_output.yml

@@ -1,28 +1,18 @@
 bookdown::gitbook:
-  css: style.css
+  dev: svglite
+  css: css/style.css
+  split_by: section
   config:
     toc:
-      collapse: section
-      after: null
-    edit:
-      link: https://github.com/vjjan91/elevMigration/edit/master/%s
-      text: "Edit"
-    sharing: no
-
-bookdown::pdf_document2:
-  keep_tex: true
-  fontsize: 10pt
-  toc-depth: 1
-  papersize: a4
-  latex_engine: xelatex
-  highlight: haddock
-  includes:
-    in_header: latex/preamble.tex
-    # before_body: before-body.tex
-    # after_body: latex/after_body.tex
-toc-depth: 1
-secnumdepth: 1
-lof: True
-lot: True
-documentclass: book
-geometry: "left=4cm, right=3cm, top=2.5cm, bottom=2.5cm"
+      collapse: none
+      before: |
+        <li><a href="./">Himalayan bird elevational migration</a></li>
+      after: |
+        <li><a href="https://bookdown.org" target="_blank">Published with bookdown</a></li>
+    edit: https://github.com/vjjan91/elevMigration/edit/master/%s
+    sharing:
+      github: yes
+      facebook: no
+
+bookdown::html_chapters:
+  css: [css/style.css, css/toc.css]