💻 Convert low-res Soroban fee diagram to Mermaid

docs/learn/fundamentals/fees-resource-limits-metering.mdx

@@ -5,6 +5,8 @@ description: "Learn how fees, resource limits, and metering work on the Stellar
 sidebar_position: 70
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+todo mermaid ! 
+
 # Fees, Resource Limits, and Metering
 
 ## Fees overview
@@ -29,7 +31,32 @@ All smart contract transactions require a resource fee in addition to an inclusi
 
 Transactions that do not execute a smart contract can be thought of as having a resource fee of zero (`resourceFee == 0`). Conversely, for smart contract transactions, you can subtract the resource fee from the total transaction fee to derive the equivalent classic transaction fee component, which is the inclusion fee.
 
-![Soroban Fees](/assets/diagrams/soroban_fees.png) _\* Diagram: Solid line boxes are what is actually present in the transaction, while dotted lines are derivable._
+```mermaid
+
+block-beta
+  columns 4
+
+  txFee["tx.fee"]:4
+
+  resourceFee["tx.v1.sorobanData.resourceFee"]:3
+  inclusionFeeTop["inclusion<br/>fee"]:1
+
+  fixed["fixed resource fee<br/>calculated based on<br/>tx.v1.sorobanData.resources.*<br/><br/>instructions<br/>read<br/>write<br/>bandwidth<br/>(size of tx)"]:2
+  refundable["refundable<br/>resource fee<br/><br/>rent<br/>events<br/>return value"]:1
+  inclusionFeeBottom["inclusion<br/>fee"]:1
+
+  style inclusionFeeTop stroke-dasharray: 8 6
+  style fixed stroke-dasharray: 8 6
+  style refundable stroke-dasharray: 8 6
+  style inclusionFeeBottom stroke-dasharray: 8 6
+
+```
+
+:::note
+
+Solid line boxes are what is actually present in the transaction, while dotted lines are derivable.
+
+:::
 
 Smart contracts on Stellar use a multidimensional resource fee model that charges fees for several resource types using [network-defined rates](https://lab.stellar.org/network-limits) on the Stellar Lab. The resource fee is calculated based on the resource consumption declared in the transaction and can fluctuate based on a mutable storage write fee (more on that in the [Storage Dynamic Pricing section](#dynamic-pricing-for-storage) below). If the transaction attempts to exceed the declared resource limits, it will fail. If the transaction uses fewer resources than declared, there will be no refunds [(with a couple of exceptions)](#refundable-and-non-refundable-resource-fees).