Update idlelib/help.html to current IDLE doc (pythonGH-22181)

Author: terryjreedy

Lib/idlelib/help.html

@@ -481,13 +481,13 @@ <h3>Automatic indentation<a class="headerlink" href="#automatic-indentation" tit
 large number of milliseconds, such as 100000000.) For imported module
 names or class or function attributes, type ‘.’.
 For filenames in the root directory, type <a class="reference internal" href="os.html#os.sep" title="os.sep"><code class="xref py py-data docutils literal notranslate"><span class="pre">os.sep</span></code></a> or
-data:<cite>os.altsep</cite> immediately after an opening quote.  (On Windows,
+<a class="reference internal" href="os.html#os.altsep" title="os.altsep"><code class="xref py py-data docutils literal notranslate"><span class="pre">os.altsep</span></code></a> immediately after an opening quote.  (On Windows,
 one can specify a drive first.)  Move into subdirectories by typing a
 directory name and a separator.</p>
-<p>Instead of waiting, or after a box is closed. open a completion box
+<p>Instead of waiting, or after a box is closed, open a completion box
 immediately with Show Completions on the Edit menu.  The default hot
 key is <kbd class="kbd docutils literal notranslate">C-space</kbd>.  If one types a prefix for the desired name
-before opening the box, the first match is displayed.
+before opening the box, the first match or near miss is made visible.
 The result is the same as if one enters a prefix
 after the box is displayed.  Show Completions after a quote completes
 filenames in the current directory instead of a root directory.</p>
@@ -975,7 +975,7 @@ <h3>Navigation</h3>
 <br />
     <br />
 
-    Last updated on Jul 08, 2020.
+    Last updated on Sep 09, 2020.
     <a href="https://docs.python.org/3/bugs.html">Found a bug</a>?
     <br />