Merge pull request #67 from merv1n34k/readme

Update README

README.md

@@ -8,26 +8,24 @@ nudoku is easily installable via many package managers.
 
 [![Packaging status](https://repology.org/badge/tiny-repos/nudoku.svg)](https://repology.org/project/nudoku/versions)
 
-### From Source ###
-
-#### Dependency ####
+#### Dependency ###
 - ncurses
 - cairo (optional: for PDF/PNG output)
 
-#### Compilation ####
+#### From source ####
 
-Get the latest .tar.xz [release](https://github.com/jubalh/nudoku/releases) and extract it.
+Get the latest `.tar.xz` [release](https://github.com/jubalh/nudoku/releases) and extract it.
 Then run:
 
-```
+```sh
 ./configure
 make
 ./src/nudoku
 ```
 
 For the git version you will have to do:
 
-```
+```sh
 git clone https://github.com/jubalh/nudoku
 cd nudoku
 autoreconf -i
@@ -41,28 +39,56 @@ Add `-DDEBUG` to `make` to have some debug output.
 nudoku can also output sudokus in PDF and PNG format (see `man nudoku` -p/-i/-n).
 You need to have cairo installed and configure with:
 
-```
+```sh
 ./configure --enable-cairo
 ```
 
-##### Usage #####
+## Usage ##
 
 For normal interactive GUI run `nudoku`.
 To print two PDF pages with 8 hard sudokus run `nudoku -p riddle.pdf -n 8 -d hard`.
 To get a PNG with an easy sudoku run `nudoku -i sudoku.png -d easy`.
 See `man nudoku` to learn more.
 
-##### I18n #####
+## I18n ##
 
-For i18n support use `make` like this:
+For i18n support you need to set `LANGUAGE` variable:
 
+```sh
+export LANGUAGE=lang
 ```
-make install
-LANGUAGE=es
-./src/nudoku
+
+Where `lang` is the translation of choice. See the list of supported languages in `po/LINGUAS` file.
+
+## Contributing ##
+
+If you plan to add/update the translation please follow these guidelines with examples:
+
+1. Fork this repository and create a new git branch with language abbreviation as a name, e.g. `es`:
+```sh
+cd nudoku # your forked git repository
+git checkout -b es
+```
+2. For new translation add language to `po/LINGUAS` and create `.po` file:
+```sh
+echo es >> po/LINGUAS && cp po/nudoku.pot po/es.po
+```
+3. Replace placeholders in uppercase in the head of the file with your information. Add translations for *(preferably)* each `msgid`.
+4. Check your `.po` file with `msgfmt` for any errors:
+```sh
+msgfmt es.po # should not produce any output
+```
+5. Push your branch to remote and create PR:
+```sh
+git push origin es
+```
+
+If you add changes to source code make sure to update potfiles as well:
+```sh
+cd po # if you inside nudoku directory
+make update-po
 ```
 
-You can replace `es` with any other language suported (suported languages are listed in `po/LINGUAS` file).
 
 ## Bugtracker ##