update README

README.md

@@ -1,32 +1,24 @@
-Note: The user "Titaniumtown" is now the primary maintainer of this repository; if you need to contact the owner contact "Titaniumtown".
-
 # HDR+ Implementation
 Original Document on the subject (by Timothy Brooks): http://timothybrooks.com/tech/hdr-plus
+Currently maintained by [Simon Gardling](https://github.com/Titaniumtown)
 
 ### Compilation instructions:
-1. Install libraw, libpng, and libjpeg.¹
-2. Download and compile llvm 3.9
-3. Install or compile the latest version Halide
-4. Go the folder you have the hdr-plus code in.
-5. From the project root directory, run the following commands:
+1. Install the [Nix](https://nixos.org/) package manager
+2. Run the below commands
 ```
+nix-shell -I shell.nix # enter a development environment
 mkdir build
 cd build
-cmake -DHALIDE_DISTRIB_DIR=$(Insert halide directory) ..
-make -j$(expr $(nproc) \+ 1)
+cmake ..
+make -j`nproc`
 ```
 
 ### HDR+ algorithm examples:
-
-There are three zip files with examples of the HDR+ algorithm at: http://www.gardling.com/hdr_plus
+There are three zip files with examples of the HDR+ algorithm at: https://www.gardling.com/hdr_plus
 
 ### Compiled Binary Usage:
 ```
 Usage: ./hdrplus [-c comp -g gain (optional)] dir_path out_img raw_img1 raw_img2 [...]
 ```
 
 The -c and -g flags change the amount of dynamic range compression and gain respectively. Although they are optional because they both have default values. 
-
-### Footnotes:
-
-¹Also to install libraw, libpng, and libjpeg on macOS run ```brew install libraw libpng libjpeg```