Update compilation instructions throughout our docs

related to https://github.com/i3/i3/issues/4086

PACKAGE-MAINTAINER

@@ -21,12 +21,14 @@ i3-sensible-terminal is used in the default configuration.
 If your distribution has a mechanism to get the preferred terminal, such as the
 x-terminal-emulator symlink in Debian, please use it in i3-sensible-terminal.
 
-On debian, compilation and installing the manpages looks like this:
+You can build i3 like you build any other software package which uses
+https://mesonbuild.com/; see
+https://mesonbuild.com/Quick-guide.html#compiling-a-meson-project
+In case you’re unfamiliar:
 
-	autoreconf -fi
-	mkdir -p build && cd build
-	../configure
-	make -j8 install
+    $ mkdir -p build && cd build
+    $ meson ..
+    $ ninja
 
 Please make sure that i3-migrate-config-to-v4 and i3-config-wizard are
 installed with i3. The Perl script is necessary to (automatically) convert v3
@@ -35,10 +37,8 @@ config with the user’s preferred modifier and should be started on the first
 start of i3 (it will automatically exit if it finds a config file).
 
 If you have any questions, ideas, hints, problems or whatever, please do not
-hesitate to contact me. I will help you out. Just drop me an E-Mail (find the
-address at https://michael.stapelberg.de/Impressum/, scroll down to bottom),
-contact me using the same address in jabber or ask on our IRC channel:
-(#i3 on irc.freenode.net).
+hesitate to contact me. I will help you out. Please see
+https://i3wm.org/contact/
 
 Thanks again for your efforts,
 Michael

docs/hacking-howto

@@ -23,8 +23,10 @@ outdated information.
 
 == Building i3
 
-You can build i3 like you build any other software package which uses meson.
-Here’s a memory refresher:
+You can build i3 like you build any other software package which uses
+https://mesonbuild.com/[The Meson Build system]; see
+https://mesonbuild.com/Quick-guide.html#compiling-a-meson-project[Quickstart
+Guide → Compiling a Meson project]. In case you’re unfamiliar:
 
     $ mkdir -p build && cd build
     $ meson ..

docs/testsuite

@@ -120,13 +120,11 @@ tests are run under Xvfb.
 ---------------------------------------
 $ cd ~/i3
 
-$ autoreconf -fi
-
 $ mkdir -p build && cd build
 
-$ ../configure
+$ meson ..
 
-$ make -j8
+$ ninja
 # output omitted because it is very long
 
 $ cd testcases
@@ -183,13 +181,11 @@ You can still use ./testcases/complete-run.pl to get the interactive progress ou
 ---------------------------------------
 $ cd ~/i3
 
-$ autoreconf -fi
-
 $ mkdir -p build && cd build
 
-$ ../configure
+$ meson ..
 
-$ make -j8
+$ ninja
 # output omitted because it is very long
 
 $ make check