doc: fix some HTML syntax errors

R=adg
CC=golang-dev
https://golang.org/cl/6458043

doc/articles/concurrency_patterns.html

@@ -17,7 +17,7 @@ and launching a goroutine that sleeps before sending on the channel:
 We can then use a <code>select</code> statement to receive from either
 <code>ch</code> or <code>timeout</code>. If nothing arrives on <code>ch</code>
 after one second, the timeout case is selected and the attempt to read from
-<cde>ch</cde> is abandoned.
+<code>ch</code> is abandoned.
 </p>
 
 {{code "/doc/progs/timeout1.go" `/select {/` `/STOP/`}}

doc/articles/image_package.html

@@ -45,7 +45,7 @@ classic algebra:
 dstr, dstg, dstb, dsta := dst.RGBA()
 srcr, srcg, srcb, srca := src.RGBA()
 _, _, _, m := mask.RGBA()
-const M = 1<<16 - 1
+const M = 1&lt;&lt;16 - 1
 // The resultant red value is a blend of dstr and srcr, and ranges in [0, M].
 // The calculation for green, blue and alpha is similar.
 dstr = (dstr*(M-m) + srcr*m) / M
@@ -130,7 +130,7 @@ much easier to type.
 A <code>Rectangle</code> is inclusive at the top-left and exclusive at the
 bottom-right. For a <code>Point p</code> and a <code>Rectangle r</code>,
 <code>p.In(r)</code> if and only if
-<code>r.Min.X <= p.X && p.X < r.Max.X</code>, and similarly for <code>Y</code>. This is analagous to how
+<code>r.Min.X &lt;= p.X &amp;&amp; p.X &lt; r.Max.X</code>, and similarly for <code>Y</code>. This is analagous to how
 a slice <code>s[i0:i1]</code> is inclusive at the low end and exclusive at the
 high end. (Unlike arrays and slices, a <code>Rectangle</code> often has a
 non-zero origin.)
@@ -193,8 +193,8 @@ way to iterate over an <code>Image</code> m's pixels looks like:
 
 <pre>
 b := m.Bounds()
-for y := b.Min.Y; y < b.Max.Y; y++ {
-	for x := b.Min.X; y < b.Max.X; x++ {
+for y := b.Min.Y; y &lt; b.Max.Y; y++ {
+	for x := b.Min.X; y &lt; b.Max.X; x++ {
 		doStuffWith(m.At(x, y))
 	}
 }

doc/articles/json_rpc_tale_of_interfaces.html

@@ -57,7 +57,7 @@ original functionality. From there it is simple to build a
 After some similar changes to the client side, this was the full extent of the
 work we needed to do on the RPC package. This whole exercise took about 20
 minutes! After tidying up and testing the new code, the
-<a href="http://code.google.com/p/go/source/diff?spec=svn9daf796ebf1cae97b2fcf760a4ab682f1f063f29&r=9daf796ebf1cae97b2fcf760a4ab682f1f063f29&format=side&path=/src/pkg/rpc/server.go">final changeset</a>
+<a href="http://code.google.com/p/go/source/diff?spec=svn9daf796ebf1cae97b2fcf760a4ab682f1f063f29&amp;r=9daf796ebf1cae97b2fcf760a4ab682f1f063f29&amp;format=side&amp;path=/src/pkg/rpc/server.go">final changeset</a>
 was submitted.
 </p>
 

doc/code.html

@@ -182,7 +182,7 @@ func Sqrt(x float64) float64 {
         // This is a terrible implementation.
         // Real code should import "math" and use math.Sqrt.
         z := 0.0
-        for i := 0; i < 1000; i++ {
+        for i := 0; i &lt; 1000; i++ {
                 z -= (z*z - x) / (2 * x)
         }
         return z

doc/install.html

@@ -41,7 +41,7 @@ proceeding. If your OS or architecture is not on the list, it's possible that
 </tr>
 <tr><td colspan="3"><hr></td></tr>
 <tr><td>FreeBSD 7 or later</td> <td>amd64, 386</td> <td>Debian GNU/kFreeBSD not supported</td></tr>
-<tr><td>Linux 2.6.23 or later with glibc</td> <td>amd64, 386, arm</td> <td>CentOS/RHEL 5.x not supported; no binary distribution for ARM yet</tr>
+<tr><td>Linux 2.6.23 or later with glibc</td> <td>amd64, 386, arm</td> <td>CentOS/RHEL 5.x not supported; no binary distribution for ARM yet</td></tr>
 <tr><td>Mac OS X 10.6/10.7</td> <td>amd64, 386</td> <td>use the gcc<sup>&#8224;</sup> that comes with Xcode</td></tr>
 <tr><td>Windows 2000 or later</td> <td>amd64, 386</td> <td>use mingw gcc<sup>&#8224;</sup>; cygwin or msys is not needed</td></tr>
 </table>
@@ -155,7 +155,7 @@ a zip archive that requires you to set some environment variables and an
 experimental MSI installer that configures your installation automatically.
 </p>
 
-<h4 id="windows_zip">Zip archive</h3>
+<h4 id="windows_zip">Zip archive</h4>
 
 <p>
 Extract the <a href="http://code.google.com/p/go/downloads/list?q=OpSys-Windows+Type%3DArchive">zip file</a>
@@ -171,7 +171,7 @@ the <code>GOROOT</code> environment variable to your chosen path.
 Add the <code>bin</code> subdirectory of your Go root (for example, <code>c:\Go\bin</code>) to to your <code>PATH</code> environment variable.
 </p>
 
-<h4 id="windows_msi">MSI installer (experimental)</h3>
+<h4 id="windows_msi">MSI installer (experimental)</h4>
 
 <p>
 Open the <a href="http://code.google.com/p/go/downloads/list?q=OpSys-Windows+Type%3DInstaller">MSI file</a>