adding a MultiFir example to the P1 collection

tools/OhmsLawExperiment.dat

+# Measurements: Ohm's Law
+#  Prec.: U: +\-0.10V, I: +\-0.10A, T: +/-0.10K
+# U[V]   I[A]  T[K]
+  0.50   0.50  293.5
+  1.00   0.89  293.8
+  1.50   1.41  295.4
+  2.00   1.67  296.8
+  2.50   2.30  299.4
+  3.00   2.59  301.0
+  3.50   2.77  303.0
+  4.00   3.57  307.4
+  4.50   3.94  310.9
+  5.00   4.24  315.1
+  5.50   4.73  318.0
+  6.00   4.87  323.2
+  6.50   5.35  327.4
+  7.00   5.74  333.7
+  7.50   5.77  338.2
+  8.00   6.17  343.1
+  8.50   6.32  350.0
+  9.00   6.83  354.7
+  9.50   6.87  358.6
+  10.00  7.17  367.9
\ No newline at end of file