docs(readme): add build from source (#874)

README.md

@@ -45,6 +45,7 @@ This will guide you through the installation.
 Download the .deb file from the [Releases page](https://github.com/boltgolt/howdy/releases) and install with gdebi.
 
 ### Arch Linux
+
 _Maintainer wanted._
 
 Install the `howdy` package from the AUR. For AUR installation instructions, take a look at this [wiki page](https://wiki.archlinux.org/index.php/Arch_User_Repository#Installing_packages).
@@ -52,6 +53,7 @@ Install the `howdy` package from the AUR. For AUR installation instructions, tak
 You will need to do some additional configuration steps. Please read the [ArchWiki entry](https://wiki.archlinux.org/index.php/Howdy) for more information.
 
 ### Fedora
+
 _Maintainer: [@luyatshimbalanga](https://github.com/luyatshimbalanga)_
 
 The `howdy` package is available as a [Fedora COPR repository](https://copr.fedorainfracloud.org/coprs/principis/howdy/), install it by simply executing the following commands in a terminal:
@@ -64,10 +66,45 @@ sudo dnf --refresh install howdy
 See the link to the COPR repository for detailed configuration steps.
 
 ### openSUSE
+
 _Maintainer: [@dmafanasyev](https://github.com/dmafanasyev)_
 
 Go to the [openSUSE wiki page](https://en.opensuse.org/SDB:Facial_authentication) for detailed installation instructions.
 
+### Building from source
+
+If you want to build Howdy from source, a few dependencies are required.
+
+#### Dependencies
+
+- Python 3.6 or higher
+  * pip
+  * setuptools
+  * wheel
+- meson version 0.64 or higher
+- ninja
+- INIReader (can be pulled from git automatically if not found)
+- libevdev
+
+To install them on Debian/Ubuntu for example:
+
+```
+sudo apt-get update && sudo apt-get install -y \
+python3 python3-pip python3-setuptools python3-wheel \
+cmake make build-essential \
+libpam0g-dev libinih-dev libevdev-dev \
+python3-dev libopencv-dev
+```
+
+#### Build
+
+```sh
+meson setup build
+meson compile -C build
+```
+
+You can also install Howdy to your system with `meson install -C build`.
+
 ## Setup
 
 After installation, Howdy needs to learn what you look like so it can recognise you later. Run `sudo howdy add` to add a face model.
@@ -107,7 +144,8 @@ Code contributions are also very welcome. If you want to port Howdy to another d
 
 Any Python errors get logged directly into the console and should indicate what went wrong. If authentication still fails but no errors are printed, you could take a look at the last lines in `/var/log/auth.log` to see if anything has been reported there.
 
-If you encounter an error that hasn't been reported yet, don't be afraid to open a new issue.
+Please first check the [wiki on common issues](https://github.com/boltgolt/howdy/wiki/Common-issues) and 
+if you encounter an error that hasn't been reported yet, don't be afraid to open a new issue.
 
 ## A note on security
 

howdy/src/pam/README.md

@@ -1,6 +1,6 @@
 # Howdy PAM module
 
-## Prepare
+## Requirements
 
 This module depends on `INIReader` and `libevdev`.
 They can be installed with these packages:
@@ -19,7 +19,7 @@ it will be automatically pulled from git at the subproject's pinned version.
 
 ``` sh
 meson setup build
-ninja -C build
+ninja -C build # or meson compile -C build
 ```
 
 ## Install

meson.build

@@ -14,6 +14,6 @@ paths_dict = {
     'log_path': logpath,
 }
 
-# We need to keep this order beause howdy-gtk defines the gtk script path
+# We need to keep this order beause howdy-gtk defines the gtk script path which is used later in howdy
 subdir('howdy-gtk')
 subdir('howdy')