pkg/tweetnacl: remove trailing whitespaces from doc.txt

pkg/tweetnacl/doc.txt

@@ -10,47 +10,47 @@
  * TweetNaCl fits into just 100 tweets while supporting all 25 of the C NaCl
  * functions used by applications. TweetNaCl is a self-contained public-domain C
  * library, so it can easily be integrated into applications.
- * 
+ *
  * NaCl (pronounced "salt") is a new easy-to-use high-speed software library for
  * network communication, encryption, decryption, signatures, etc. NaCl's goal is
  * to provide all of the core operations needed to build higher-level
  * cryptographic tools.
- * 
+ *
  * Of course, other libraries already exist for these core operations. NaCl
  * advances the state of the art by improving security, by improving usability,
  * and by improving speed.
- * 
+ *
  * (from https://nacl.cr.yp.to/ and http://tweetnacl.cr.yp.to/)
- * 
+ *
  * You can find the API and more information [here](https://nacl.cr.yp.to/), since
  * the sources are not documented due to the aim for fitting in 100 tweets.
- * 
+ *
  * ## Requirements
  *
  * TweetNaCl requires more than 2K of stack, so beware that you're allocating at
  * least `THREAD_STACKSIZE_DEFAULT + 2048` bytes.
- * 
+ *
  * You can do it easily by adding:
- * 
+ *
  * ```makefile
  * CFLAGS += '-DTHREAD_STACKSIZE_MAIN=(THREAD_STACKSIZE_DEFAULT + 2048)'
  * ```
- * 
+ *
  * to your makefile.
- * 
+ *
  * ## Usage
  *
  * Just add it as a package in your application:
- * 
+ *
  * ```makefile
  * USEPKG += tweetnacl
  * ```
- * 
+ *
  * And don't forget to include the header:
- * 
+ *
  * ```c
  * #include <tweetnacl.h>
  * ```
  *
  * @see     https://tweetnacl.cr.yp.to/
- */
+ */