Depend on parallel, doc improvements

By depending on parallel instead of importing it, functions to set up
and stop a cluster are always available when mkin is loaded.

The use of multicore processing in mmkin on Windows is now documented in
the help file, which brings mkin closer to a version 1.0 #9.

7 files changed, 37 insertions, 0 deletions

diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.css b/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.css
new file mode 100644
index 00000000..07aee5fc
--- /dev/null
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.css
@@ -0,0 +1,4 @@
+/* Styles for section anchors */
+a.anchor-section {margin-left: 10px; visibility: hidden; color: inherit;}
+a.anchor-section::before {content: '#';}
+.hasAnchor:hover a.anchor-section {visibility: visible;}
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.js b/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.js
new file mode 100644
index 00000000..570f99a0
--- /dev/null
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/anchor-sections-1.0/anchor-sections.js
@@ -0,0 +1,33 @@
+// Anchor sections v1.0 written by Atsushi Yasumoto on Oct 3rd, 2020.
+document.addEventListener('DOMContentLoaded', function() {
+  // Do nothing if AnchorJS is used
+  if (typeof window.anchors === 'object' && anchors.hasOwnProperty('hasAnchorJSLink')) {
+    return;
+  }
+
+  const h = document.querySelectorAll('h1, h2, h3, h4, h5, h6');
+
+  // Do nothing if sections are already anchored
+  if (Array.from(h).some(x => x.classList.contains('hasAnchor'))) {
+    return null;
+  }
+
+  // Use section id when pandoc runs with --section-divs
+  const section_id = function(x) {
+    return ((x.classList.contains('section') || (x.tagName === 'SECTION'))
+            ? x.id : '');
+  };
+
+  // Add anchors
+  h.forEach(function(x) {
+    const id = x.id || section_id(x.parentElement);
+    if (id === '') {
+      return null;
+    }
+    let anchor = document.createElement('a');
+    anchor.href = '#' + id;
+    anchor.classList = ['anchor-section'];
+    x.classList.add('hasAnchor');
+    x.appendChild(anchor);
+  });
+});
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p10-1.png b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p10-1.png
index 3e9c743f..38b251ea 100644
--- a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p10-1.png
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p10-1.png
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p13-1.png b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p13-1.png
index 029e6a17..ce177190 100644
--- a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p13-1.png
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p13-1.png
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p15a-1.png b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p15a-1.png
index 24cb27d8..c5759a5b 100644
--- a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p15a-1.png
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p15a-1.png
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p16-1.png b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p16-1.png
index f3fa460e..b61f28e2 100644
--- a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p16-1.png
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p16-1.png
diff --git a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p7-1.png b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p7-1.png
index d6ae1fa4..515e9095 100644
--- a/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p7-1.png
+++ b/docs/dev/articles/web_only/NAFTA_examples_files/figure-html/p7-1.png