ministat.1: Match actual output

Fix a documentation discrepancy, where the implementation was updated to
use uncertainty propagation for the ratio of means, but the example
output in the manual page was left unchanged.

Update the manual page example from 70.7384% to 102.3% to reflect the
actual output.

While here, also update the example in the README.

Reviewed by:	ziaee
Fixes:		a304ad90e9 ("Reduce the bogosity of ministat's % difference calculations.")
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D59157

usr.bin/ministat/README

@@ -1,8 +1,7 @@
-
 A small tool to do the statistics legwork on benchmarks etc.
 
 Prepare your data into two files, one number per line
-run 
+run
 	./ministat data_before data_after
 
 and see what it says.
@@ -41,9 +40,7 @@ x   5         0.133         0.137         0.136        0.1354  0.0015165751
 +   5         0.139          0.14         0.139        0.1394 0.00054772256
 Difference at 95.0% confidence
         0.004 +/- 0.00166288
-        2.95421% +/- 1.22812%
+        2.95421% +/- 1.26027%
         (Student's t, pooled s = 0.00114018)
 
 Here we have a clearcut difference, not very big, but clear and unambiguous.
-
-

usr.bin/ministat/ministat.1

@@ -24,7 +24,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd November 13, 2025
+.Dd August 24, 2026
 .Dt MINISTAT 1
 .Os
 .Sh NAME
@@ -149,7 +149,7 @@ x   7         50        750        200        300    238.04761
 +   5        150        930        500        540    299.08193
 Difference at 80.0% confidence
       240 +/- 212.215
-      80% +/- 70.7384%
+      80% +/- 102.3%
       (Student's t, pooled s = 264.159)
 .Ed
 .Pp