update installation instructions in the README"

This reverts commit a5ea04c.

Author: etpinard

README.md

@@ -16,6 +16,17 @@ Follow [@plotlygraphs](https://twitter.com/plotlygraphs) on Twitter for Orca ann
 
 ## Installation
 
+### Method 1: conda
+If you have conda installed, you can easily install Orca from the plotly
+conda channel using:
+```
+$ conda install -c plotly plotly-orca
+```
+
+which makes the `orca` executable available on the path of current conda
+environment.
+
+### Method 2: npm
 If you have Node.js installed (recommended v8.x), you can easily install Orca
 using npm as:
 
@@ -25,11 +36,13 @@ $ npm install -g electron@1.8.4 orca
 
 which makes the `orca` executable available in your path.
 
+### Method 3: Standalone binaries 
+
 Alternatively, you can download the standalone Orca binaries corresponding to
 your operating system from the
 [release](https://github.com/plotly/orca/releases) page. Then, on
 
-### Mac OS
+#### Mac OS
 
 - Unzip `mac-release.zip` from your `Downloads/` folder
 - Double-click on `orca-X.Y.Z.dmg` file, that should open an installation window
@@ -38,14 +51,14 @@ your operating system from the
 - Right-click on the orca icon and click on _Open_, this should open an _Installation Succeeded_ window
 - Open the terminal and start using Orca!
 
-### Windows
+#### Windows
 
 - Extract the `window-release.zip` file
 - In the `release` folder, double-click on `orca Setup X.Y.Z`, this will create an orca icon on your Desktop
 - Right-click on the orca icon, then click on _Properties_ and copy the _Starts in_ field
 - In the command prompt, run `PATH %PATH%;<paste the "Starts in" field here>`
 
-### Linux
+#### Linux
 
 - Run `$ chmod +x orca-X.Y.Z-x86_64.AppImage`
 - Add it to your `$PATH`