SPI.md tidy up table.

spi/SPI.md

@@ -21,16 +21,16 @@ Any SPI interface may be used. The table below assumes a Pyboard running SPI(2)
 as per the test program. To wire up a single EEPROM chip, connect to a Pyboard
 as below. Pin numbers assume a PDIP package (8 pin plastic dual-in-line).
 
-| EEPROM  |  PB | Signal |
-|:-------:|:---:|:------:|
-| 1 CS    | Y5  | SS/    |
-| 2 SO    | Y7  | MISO   |
-| 3 WP/   | 3V3 | 3V3    |
-| 4 Vss   | Gnd | Gnd    |
-| 5 SI    | Y8  | MOSI   |
-| 6 SCK   | Y6  | SCK    |
-| 7 HOLD/ | 3V3 | 3V3    |
-| 8 Vcc   | 3V3 | 3V3    |
+| EEPROM  | Signal |  PB | Signal |
+|:-------:|:------:|:---:|:------:|
+| 1       |  CS    | Y5  | SS/    |
+| 2       |  SO    | Y7  | MISO   |
+| 3       |  WP/   | 3V3 | 3V3    |
+| 4       |  Vss   | Gnd | Gnd    |
+| 5       |  SI    | Y8  | MOSI   |
+| 6       |  SCK   | Y6  | SCK    |
+| 7       |  HOLD/ | 3V3 | 3V3    |
+| 8       |  Vcc   | 3V3 | 3V3    |
 
 For multiple chips a separate CS pin must be assigned to each chip: each one
 must be wired to a single chip's CS line. Multiple chips should have 3V3, Gnd,