Links must have a trailing slash if not pointing to a file

[pcolmer]

The static website configuration is going to be changed soon in a way that will make it more secure but have the side-effect that links like /pinout will no longer redirect to /pinout/. Therefore all static links that are not pointing to a file (e.g. /pinout) must be updated so that a trailing slash is added.

For reference, here are the links that would break under these conditions:

/pinout/404.html:
   /pinout
/pinout/aerocore2.html:
   /pinout
/pinout/arrow_audio_mezzanine.html:
   /pinout
/pinout/arrow_linksprite_mezzanine_kit.html:
   /pinout
/pinout/boards.html:
   /pinout
/pinout/d3_camera_mezzanine.html:
   /pinout
/pinout/ground.html:
   /pinout
/pinout/grove_seeed_sensor_mezzanine.html:
   /pinout
/pinout/i2c.html:
   /pinout
/pinout/index.html:
   /pinout
/pinout/lora_mezzanine_card_for_96board.html:
   /pinout
/pinout/mipi_adapter_mezzanine_aistarvision.html:
   /pinout
/pinout/neonkey_mezzanine.html:
   /pinout
/pinout/nextbio_nb_2023_s2.html:
   /pinout
/pinout/pin10_spi0_din.html:
   /pinout
/pinout/pin11_uart1_txd.html:
   /pinout
/pinout/pin12_spi0_cs.html:
   /pinout
/pinout/pin13_uart1_rxd.html:
   /pinout
/pinout/pin14_spi0_dout.html:
   /pinout
/pinout/pin15_i2c0_scl.html:
   /pinout
/pinout/pin16_pcm_fs.html:
   /pinout
/pinout/pin17_i2c0_sda.html:
   /pinout
/pinout/pin18_pcm_clk.html:
   /pinout
/pinout/pin19_i2c1_scl.html:
   /pinout
/pinout/pin20_pcm_do.html:
   /pinout
/pinout/pin21_i2c1_sda.html:
   /pinout
/pinout/pin22_pcm_di.html:
   /pinout
/pinout/pin23_gpio_a.html:
   /pinout
/pinout/pin24_gpio_b.html:
   /pinout
/pinout/pin25_gpio_c.html:
   /pinout
/pinout/pin26_gpio_d.html:
   /pinout
/pinout/pin27_gpio_e.html:
   /pinout
/pinout/pin28_gpio_f.html:
   /pinout
/pinout/pin29_gpio_g.html:
   /pinout
/pinout/pin30_gpio_h.html:
   /pinout
/pinout/pin31_gpio_i.html:
   /pinout
/pinout/pin32_gpio_j.html:
   /pinout
/pinout/pin33_gpio_k.html:
   /pinout
/pinout/pin34_gpio_l.html:
   /pinout
/pinout/pin35_1v8.html:
   /pinout
/pinout/pin36_sys_dcin.html:
   /pinout
/pinout/pin37_5v.html:
   /pinout
/pinout/pin38_sys_dcin.html:
   /pinout
/pinout/pin3_uart0_cts.html:
   /pinout
/pinout/pin4_pwr_btn_n.html:
   /pinout
/pinout/pin5_uart0_txd.html:
   /pinout
/pinout/pin6_rst_btn_n.html:
   /pinout
/pinout/pin7_uart0_rxd.html:
   /pinout
/pinout/pin8_spi0_sclk.html:
   /pinout
/pinout/pin9_uart0_rts.html:
   /pinout
/pinout/poe_ethernet_mezzanine.html:
   /pinout
/pinout/secure96.html:
   /pinout
/pinout/shiratech_lte.html:
   /pinout
/pinout/spi.html:
   /pinout
/pinout/stm32_sensor_mezzanine_board_mbedtm_enabled.html:
   /pinout
/pinout/uart.html:
   /pinout
/pinout/uart_serial_mezzanine.html:
   /pinout