adds bash basics section

basics.html

@@ -363,6 +363,23 @@
             - do not type brackets they just mean argument optional
           </section>
 
+          <section id="cli-bash-basics" data-markdown>
+            ## command line
+            ### bash basics
+
+            ```bash
+            pwd           # print working directory
+            ls [dir]      # list directory contents
+            echo msg      # print message
+            cd [dir]      # change directory
+            mkdir dir     # create directory
+            rmdir dir     # remove directory
+            rm file       # remove file
+            cp src dest   # copy from source to destination
+            mv src dest   # move / rename
+            ```
+          </section>
+
           <section id="cli-git" data-markdown>
             ## command line
             ### git syntax