Update conf.py from git tag, fix sphinx warnings (#5716)

Fixes #5671

Implements https://protips.readthedocs.io/git-tag-version.html

Fix a myriad of minor Sphinx warnings generated in the docs.

doc/gdb.rst

@@ -76,13 +76,13 @@ ELF format version of it (which includes needed debug symbols).
 
 Under Linux these files are stored in ``/tmp/arduino_build_*`` and the following command will help locate the right file for your app:
 
-.. code:: cpp
+.. code:: bash
 
     find /tmp -name "*.elf" -print
 
 Under Windows these files are stored in ``%userprofile%\AppData\Local\Temp\arduino_build_*`` and the following command will help locate the right file for your app:
 
-.. code:: cpp
+.. code:: bash
 
     dir %userprofile%\appdata\*.elf /s/b
 
@@ -98,19 +98,19 @@ directory.
 
 Linux
 
-.. code:: cpp
+.. code:: bash
 
     ~/.arduino15/packages/esp8266/hardware/xtensa-lx106-elf/bin/xtensa-lx106-elf-gdb
 
 Windows (Using Board Manager version)
 
-.. code:: cpp
+.. code:: bash
 
     %userprofile%\AppData\Local\Arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\2.5.0-3-20ed2b9\bin\xtensa-lx106-elf-gdb.exe
 
 Windows (Using Git version)
 
-.. code:: cpp
+.. code:: bash
 
     %userprofile%\Documents\Arduino\hardware\esp8266com\esp8266\tools\xtensa-lx106-elf\bin\xtensa-lx106-elf-gdb.exe
 
@@ -124,7 +124,7 @@ Apply the GDB Configurations
 At the ``(gdb)`` prompt, enter the following options to configure GDB for the
 ESP8266 memory map and configuration:
 
-.. code:: cpp
+.. code:: bash
 
     set remote hardware-breakpoint-limit 1
     set remote hardware-watchpoint-limit 1
@@ -142,7 +142,7 @@ ESP8266 memory map and configuration:
 
 Now tell GDB where your compiled ELF file is located:
 
-.. code:: cpp
+.. code:: bash
 
     file /tmp/arduino_build_257110/sketch_dec26a.ino.elf
 
@@ -153,13 +153,13 @@ Once GDB has been configured properly and loaded your debugging symbols, connect
 it to the ESP with the command (replace the ttyUSB0 or COM9 with your ESP's serial
 port):
 
-.. code:: cpp
+.. code:: bash
 
     target remote /dev/ttyUSB0
 
 or
 
-.. code:: cpp
+.. code:: bash
 
     target remote \\.\COM9
 
@@ -191,7 +191,7 @@ Create a new sketch and paste the following code into it:
 Save it and then build and upload to your ESP8266.  On the Serial monitor you
 should see something like
 
-.. code:: cpp
+.. code:: bash
 
     1
     2
@@ -203,7 +203,7 @@ Now close the Serial Monitor.
 
 Open a command prompt and find the ELF file:
 
-.. code:: cpp
+.. code:: bash
 
     earle@server:~$ find /tmp -name "*.elf" -print
     /tmp/arduino_build_257110/testgdb.ino.elf
@@ -215,7 +215,7 @@ the one we just built, ``testgdb.ino.elf``.
 
 Open up the proper ESP8266-specific GDB
 
-.. code:: cpp
+.. code:: bash
 
     earle@server:~$ ~/.arduino15/packages/esp8266/hardware/xtensa-lx106-elf/bin/xtensa-lx106-elf-gdb
     GNU gdb (GDB) 8.2.50.20180723-git
@@ -238,7 +238,7 @@ Open up the proper ESP8266-specific GDB
 We're now at the GDB prompt, but nothing has been set up for the ESP8266
 and no debug information has been loaded.  Cut-and-paste the setup options:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) set remote hardware-breakpoint-limit 1
     (gdb) set remote hardware-watchpoint-limit 1
@@ -257,14 +257,14 @@ and no debug information has been loaded.  Cut-and-paste the setup options:
 
 And tell GDB where the debugging info ELF file is located:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) file /tmp/arduino_build_257110/testgdb.ino.elf
     Reading symbols from /tmp/arduino_build_257110/testgdb.ino.elf...done.
 
 Now, connect to the running ESP8266:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb)     target remote /dev/ttyUSB0
     Remote debugging using /dev/ttyUSB0
@@ -279,7 +279,7 @@ output will be displayed on the GDB console..
 
 Continue the running app to see the serial output:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) cont
     Continuing.
@@ -291,7 +291,8 @@ Continue the running app to see the serial output:
 
 The app is back running and we can stop it at any time using ``Ctrl-C``:
 
-.. code:: cpp 
+.. code:: bash 
+
     113
     ^C
     Program received signal SIGINT, Interrupt.
@@ -301,7 +302,7 @@ The app is back running and we can stop it at any time using ``Ctrl-C``:
 At this point we can set a breakpoint on the main ``loop()`` and restart
 to get into our own code:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) break loop
     Breakpoint 1 at 0x40202e33: file /home/earle/Arduino/sketch_dec26a/sketch_dec26a.ino, line 10.
@@ -316,7 +317,8 @@ to get into our own code:
 
 Let's examine the local variable:
 
-.. code:: cpp
+.. code:: bash
+
     (gdb) next
     loop () at /home/earle/Arduino/sketch_dec26a/sketch_dec26a.ino:13
     13      Serial.printf("%d\n", cnt++);
@@ -326,7 +328,7 @@ Let's examine the local variable:
 
 And change it:
 
-.. code:: cpp
+.. code:: bash
 
     $2 = 114
     (gdb) set cnt = 2000
@@ -336,7 +338,7 @@ And change it:
 
 And restart the app and see our changes take effect:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) cont
     Continuing.
@@ -352,7 +354,7 @@ And restart the app and see our changes take effect:
 
 Looks like we left the breakpoint on loop(), let's get rid of it and try again:
 
-.. code:: cpp
+.. code:: bash
 
     (gdb) delete
     Delete all breakpoints? (y or n) y