Update README.md (#7)

The architecture figure was broken

README.md

@@ -14,7 +14,8 @@ The solver component consists of three concurrent [Actors](https://en.wikipedia.
 * The **AMPL Solver** implementing the mathematical solver finding the configuration that maximises the utility function for the provided application execution context. A Mathematical Programming Language ([AMPL](https://ampl.com/)) is used to formulate the constraint mathematical programming problem calling a back end mathematical solver. Many different solvers can be used, both commercial and open source, and the current implementation uses the open source solver [Couenne](https://github.com/coin-or/Couenne) from the [Computational Infrastructure for Operations Research (COIN-OR)](https://www.coin-or.org/).
 
 A Class-Actor-Communication diagram is shwon below. The green components are other parts of the NebulOuS Optimizer module, and the gray components are other NebulOuS componts intaracting with the Solver Component. 
-![Class - Actor - Communication diagram for the Solver Component](Optimizer architecture-Solver.drawio.png) 
+
+![Architecture diagram](https://github.com/eu-nebulous/optimiser-solver/blob/main/Optimizer%20architecture-Solver.drawio.png)
 
 
 ## Messages
@@ -190,4 +191,4 @@ The Solver Component actors and the Theron++ library uses features of the latest
 The AMPL Solver actor uses the [AMPL C++ Application Programming Interface (API)](https://ampl.com/api/latest/cpp/) to parse and interpret the constraint optimisation problem file, and to call the back-end mathematical programme solvers
 
 ##  License
-The software is copyleft open source provided under the [Mozilla Public License version 2.0](https://www.mozilla.org/en-US/MPL/2.0/).
+The software is copyleft open source provided under the [Mozilla Public License version 2.0](https://www.mozilla.org/en-US/MPL/2.0/).