doc: consistently use ```sh tags for correct shell highlighting

doc/build-unix.md

@@ -9,15 +9,17 @@ Note
 Always use absolute paths to configure and compile Dash Core and the dependencies.
 For example, when specifying the path of the dependency:
 
+```sh
 ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX
+```
 
-Here BDB_PREFIX must be an absolute path - it is defined using $(pwd) which ensures
+Here `BDB_PREFIX` must be an absolute path - it is defined using $(pwd) which ensures
 the usage of the absolute path.
 
 To Build
 ---------------------
 
-```bash
+```sh
 ./autogen.sh
 ./configure
 make
@@ -59,7 +61,9 @@ memory available when compiling Dash Core. On systems with less, gcc can be
 tuned to conserve memory with additional CXXFLAGS:
 
 
+```sh
 ./configure CXXFLAGS="--param ggc-min-expand=1 --param ggc-min-heapsize=32768"
+```
 
 
 ## Linux Distribution Specific Instructions
@@ -70,11 +74,15 @@ tuned to conserve memory with additional CXXFLAGS:
 
 Build requirements:
 
+```sh
 sudo apt-get install build-essential libtool autotools-dev automake pkg-config bsdmainutils bison python3
+```
 
 Now, you can either build from self-compiled [depends](/depends/README.md) or install the required dependencies:
 
+```sh
 sudo apt-get install libevent-dev libboost-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev
+```
 
 Berkeley DB is required for the wallet.
 
@@ -87,21 +95,29 @@ Otherwise, you can build Berkeley DB [yourself](#berkeley-db).
 
 SQLite is required for the wallet:
 
+```sh
 sudo apt-get install libsqlite3-dev
+```
 
 To build Dash Core without wallet, see [*Disable-wallet mode*](#disable-wallet-mode)
 
 Optional port mapping libraries (see: `--with-miniupnpc` and `--with-natpmp`):
 
+```sh
 sudo apt-get install libminiupnpc-dev libnatpmp-dev
+```
 
 ZMQ dependencies (provides ZMQ API):
 
+```sh
 sudo apt-get install libzmq3-dev
+```
 
 GMP dependencies (provides platform-optimized routines):
 
+```sh
 sudo apt-get install libgmp-dev
+```
 
 GUI dependencies:
 
@@ -111,15 +127,21 @@ To build without GUI pass `--without-gui`.
 
 To build with Qt 5 you need the following:
 
+```sh
 sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools
+```
 
 Additionally, to support Wayland protocol for modern desktop environments:
 
+```sh
 sudo apt-get install qtwayland5
+```
 
 libqrencode (optional) can be installed with:
 
+```sh
 sudo apt-get install libqrencode-dev
+```
 
 Once these are installed, they will be found by configure and a dash-qt executable will be
 built by default.
@@ -131,15 +153,21 @@ built by default.
 
 Build requirements:
 
+```sh
 sudo dnf install gcc-c++ libtool make autoconf automake python3
+```
 
 Now, you can either build from self-compiled [depends](/depends/README.md) or install the required dependencies:
 
+```sh
 sudo dnf install libevent-devel boost-devel
+```
 
 Berkeley DB is required for the wallet:
 
+```sh
 sudo dnf install libdb4-devel libdb4-cxx-devel
+```
 
 Newer Fedora releases, since Fedora 33, have only `libdb-devel` and `libdb-cxx-devel` packages, but these will install
 Berkeley DB 5.3 or later. This will break binary wallet compatibility with the distributed executables, which
@@ -150,21 +178,29 @@ Otherwise, you can build Berkeley DB [yourself](#berkeley-db).
 
 SQLite is required for the wallet:
 
+```sh
 sudo dnf install sqlite-devel
+```
 
 To build Dash Core without wallet, see [*Disable-wallet mode*](#disable-wallet-mode)
 
 Optional port mapping libraries (see: `--with-miniupnpc` and `--with-natpmp`):
 
+```sh
 sudo dnf install miniupnpc-devel libnatpmp-devel
+```
 
 ZMQ dependencies (provides ZMQ API):
 
+```sh
 sudo dnf install zeromq-devel
+```
 
 GMP dependencies (provides platform-optimized routines):
 
+```sh
 sudo dnf install gmp-devel
+```
 
 GUI dependencies:
 
@@ -174,15 +210,21 @@ To build without GUI pass `--without-gui`.
 
 To build with Qt 5 you need the following:
 
+```sh
 sudo dnf install qt5-qttools-devel qt5-qtbase-devel
+```
 
 Additionally, to support Wayland protocol for modern desktop environments:
 
+```sh
 sudo dnf install qt5-qtwayland
+```
 
 libqrencode (optional) can be installed with:
 
+```sh
 sudo dnf install qrencode-devel
+```
 
 Once these are installed, they will be found by configure and a dash-qt executable will be
 built by default.
@@ -213,7 +255,7 @@ It is recommended to use Berkeley DB 4.8. If you have to build it yourself,
 you can use [the installation script included in contrib/](contrib/install_db4.sh)
 like so:
 
-```shell
+```sh
 ./contrib/install_db4.sh `pwd`
 ```
 
@@ -293,19 +335,23 @@ Additional Configure Flags
 --------------------------
 A list of additional configure flags can be displayed with:
 
+```sh
 ./configure --help
+```
 
 
 Setup and Build Example: Arch Linux
 -----------------------------------
 This example lists the steps necessary to setup and build a command line only, non-wallet distribution of the latest changes on Arch Linux:
 
+```sh
 pacman -S git base-devel boost libevent python
 git clone https://github.com/dashpay/dash.git
 cd dash/
 ./autogen.sh
 ./configure --disable-wallet --without-gui --without-miniupnpc
 make check
+```
 
 Note:
 Enabling wallet support requires either compiling against a Berkeley DB newer than 4.8 (package `db`) using `--with-incompatible-bdb`,