Fix typo in core-rsync examples

commands/core/core.drush.inc

@@ -281,7 +281,7 @@ function core_drush_command() {
       'exclude-other-sites' => 'Exclude all directories in "sites/" except for "sites/all" and the site directory for the site being synced.  Note: if the site directory is different between the source and destination, use --exclude-sites followed by "drush rsync @from:%site @to:%site"',
       'exclude-paths' => 'List of paths to exclude, seperated by : (Unix-based systems) or ; (Windows).',
       'include-paths' => 'List of paths to include, seperated by : (Unix-based systems) or ; (Windows).',
-      '{rsync-option-name}' => "Replace {rsync-option-name} with the rsync option (or option='value') that you would like to pass through to rsync. Examples include --delete, --exclude=*.sql, --filter='merge /etc/rsync/default.rules', etc. See the rsync documentation for a complete explaination of all the rsync options and values.",
+      '{rsync-option-name}' => "Replace {rsync-option-name} with the rsync option (or option='value') that you would like to pass through to rsync. Examples include --delete, --exclude=*.sql, --filter='merge /etc/rsync/default.rules', etc. See the rsync documentation for a complete explanation of all the rsync options and values.",
       'rsync-version' => 'Set to the version of rsync you are using to signal Drush to go into backwards-compatibility mode when using very old versions of rsync. For example, --rsync-version=2.6.8 or earlier will cause Drush to avoid the --remove-source-files flag.',
 
     ),