Update to reveal.js 4.1.2 (#136)

- New tools/ script to manually keep step for updates
- Plugins are all updated
- Template update following latest Pandoc version
- updated README for documentation
- Help page updated 
- See other change in NEWS file
diff --git a/inst/reveal.js-4.1.2/test/assets/external-script-a.js b/inst/reveal.js-4.1.2/test/assets/external-script-a.js
new file mode 100644
index 0000000..cbc8da1
--- /dev/null
+++ b/inst/reveal.js-4.1.2/test/assets/external-script-a.js
@@ -0,0 +1 @@
+window.externalScriptSequence += 'A';
\ No newline at end of file
diff --git a/inst/reveal.js-4.1.2/test/assets/external-script-b.js b/inst/reveal.js-4.1.2/test/assets/external-script-b.js
new file mode 100644
index 0000000..e5bca5a
--- /dev/null
+++ b/inst/reveal.js-4.1.2/test/assets/external-script-b.js
@@ -0,0 +1 @@
+window.externalScriptSequence += 'B';
\ No newline at end of file
diff --git a/inst/reveal.js-4.1.2/test/assets/external-script-c.js b/inst/reveal.js-4.1.2/test/assets/external-script-c.js
new file mode 100644
index 0000000..7d4ccf6
--- /dev/null
+++ b/inst/reveal.js-4.1.2/test/assets/external-script-c.js
@@ -0,0 +1 @@
+window.externalScriptSequence += 'C';
\ No newline at end of file
diff --git a/inst/reveal.js-4.1.2/test/assets/external-script-d.js b/inst/reveal.js-4.1.2/test/assets/external-script-d.js
new file mode 100644
index 0000000..1c5925b
--- /dev/null
+++ b/inst/reveal.js-4.1.2/test/assets/external-script-d.js
@@ -0,0 +1 @@
+window.externalScriptSequence += 'D';
\ No newline at end of file