Mention the FreeBSD port

Also add generic instructions for other BSD systems.

Ref. dynare#1824

_includes/download-snapshot.html

@@ -10,7 +10,10 @@
   <label class="dynare_label" for="snapshot_tab3">GNU/Linux</label>
 
   <input class="dynare_input" id="snapshot_tab4" type="radio" name="snapshot_tabs">
-  <label class="dynare_label" for="snapshot_tab4">Source</label>
+  <label class="dynare_label" for="snapshot_tab4">BSD</label>
+
+  <input class="dynare_input" id="snapshot_tab5" type="radio" name="snapshot_tabs">
+  <label class="dynare_label" for="snapshot_tab5">Source</label>
 
   <section class="dynare_section" id="snapshot_content1">
     <p>
@@ -63,6 +66,17 @@
   </section>
 
   <section class="dynare_section" id="snapshot_content4">
+    <p>
+      Snapshots are not available for BSD systems. Users should
+      compile from source available in
+      the <a href="https://git.dynare.org/Dynare/dynare">Dynare Git
+      repository</a>, as explained on
+      the <a href="https://git.dynare.org/Dynare/dynare/blob/master/README.md">Dynare
+      README.md</a> page.
+    </p>
+  </section>
+
+  <section class="dynare_section" id="snapshot_content5">
     <p>Source code, not needed by most users.</p>
     <div class="download_table">
       {% include snapshot/download-snapshot-source.html %}

_includes/download-stable.html

@@ -10,7 +10,10 @@
   <label class="dynare_label" for="stable_tab3">GNU/Linux</label>
 
   <input class="dynare_input" id="stable_tab4" type="radio" name="stable_tabs">
-  <label class="dynare_label" for="stable_tab4">Source</label>
+  <label class="dynare_label" for="stable_tab4">BSD</label>
+
+  <input class="dynare_input" id="stable_tab5" type="radio" name="stable_tabs">
+  <label class="dynare_label" for="stable_tab5">Source</label>
 
   <section class="dynare_section" id="stable_content1">
     <p>
@@ -76,6 +79,18 @@
   </section>
 
   <section class="dynare_section" id="stable_content4">
+    <p>
+      There is a <a href="https://www.freshports.org/science/dynare/">FreeBSD
+      port for Dynare</a>. It can be installed with:
+      <code>pkg install dynare</code>.
+    </p>
+    <p>
+      For other BSD systems, you need to recompile Dynare from source, as
+      explained in the <tt>README.md</tt> file.
+    </p>
+  </section>
+
+  <section class="dynare_section" id="stable_content5">
     <p>
       Source code, not needed by most users.
     </p>

_sass/dynare.scss

@@ -356,7 +356,8 @@ label.dynare_label:before {
 label.dynare_label[for*='1']:before { font-family: 'Font Awesome 5 Brands' !important; font-weight: 400; content: '\f17a'; }
 label.dynare_label[for*='2']:before { font-family: 'Font Awesome 5 Brands' !important; font-weight: 400; content: '\f179'; }
 label.dynare_label[for*='3']:before { font-family: 'Font Awesome 5 Brands' !important; font-weight: 400; content: '\f17c'; }
-label.dynare_label[for*='4']:before { font-family: 'Font Awesome 5 Free' !important; font-weight: 900; content: '\f121'; }
+label.dynare_label[for*='4']:before { font-family: 'Font Awesome 5 Brands' !important; font-weight: 400; content: '\f3a4'; }
+label.dynare_label[for*='5']:before { font-family: 'Font Awesome 5 Free' !important; font-weight: 900; content: '\f121'; }
 
 label.dynare_label:hover {
     color: $download-tab-label-hover-color;
@@ -374,10 +375,12 @@ input.dynare_input:checked + label {
 #stable_tab2:checked ~ #stable_content2,
 #stable_tab3:checked ~ #stable_content3,
 #stable_tab4:checked ~ #stable_content4,
+#stable_tab5:checked ~ #stable_content5,
 #snapshot_tab1:checked ~ #snapshot_content1,
 #snapshot_tab2:checked ~ #snapshot_content2,
 #snapshot_tab3:checked ~ #snapshot_content3,
-#snapshot_tab4:checked ~ #snapshot_content4 {
+#snapshot_tab4:checked ~ #snapshot_content4,
+#snapshot_tab5:checked ~ #snapshot_content5 {
   display: block;
 }