doc/go1.5.html: fix typo

Change-Id: I193b416ac91b4fa9234d30a1c1c58b3f0a71f398
Reviewed-on: https://go-review.googlesource.com/11543Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

doc/go1.5.html

@@ -130,7 +130,7 @@ The old names <code>6g</code>, <code>8g</code> and so on are gone; instead there
 is just one binary, accessible as <code>go</code> <code>tool</code> <code>compile</code>,
 that compiles Go source into binaries suitable for the architecture and operating system
 specified by <code>$GOARCH</code> and <code>$GOOS</code>.
-Simlarly, there is now one linker (<code>go</code> <code>tool</code> <code>link</code>)
+Similarly, there is now one linker (<code>go</code> <code>tool</code> <code>link</code>)
 and one assembler (<code>go</code> <code>tool</code> <code>asm</code>).
 The linker was translated automatically from the old C implementation,
 but the assembler is a new native Go implementation discussed