doc: improve wget man-page

* correct formatting of synopsis
* improve description of TCP SACK configuration

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/doc/usage/cmd/wget.rst b/doc/usage/cmd/wget.rst
index 4fcfa03..e1e7f8d 100644
--- a/doc/usage/cmd/wget.rst
+++ b/doc/usage/cmd/wget.rst
@@ -7,6 +7,7 @@
 --------
 
 ::
+
     wget address [[hostIPaddr:]path]
 
 Description
@@ -52,8 +53,8 @@
 
 The command is only available if CONFIG_CMD_WGET=y.
 
-CONFIG_PROT_TCP_SACK can be turned on for the TCP SACK options. This will
-help increasing the downloading speed.
+TCP Selective Acknowledgments can be enabled via CONFIG_PROT_TCP_SACK=y.
+This will improve the download speed.
 
 Return value
 ------------