cleanup code a bit

Author: gnidan

packages/web/spec/program/example.mdx

@@ -26,8 +26,7 @@ code {
     return;
   }
 
-  let localValue = storedValue;
-  localValue = localValue + 1;
+  let localValue = storedValue + 1;
   storedValue = localValue;
 }
 `}]}
@@ -163,7 +162,7 @@ code {
         mnemonic: "SLOAD"
       },
       context: ({ findSourceRange }) => ({
-        code: findSourceRange("let localValue = storedValue;"),
+        code: findSourceRange("storedValue", { after: "let localValue" }),
         variables: [{
           identifier: "storedValue",
           type: {
@@ -175,17 +174,6 @@ code {
             slot: 0
           },
           declaration: findSourceRange("[0] storedValue: uint256")
-        }, {
-          identifier: "localValue",
-          type: {
-            kind: "uint",
-            bits: 256
-          },
-          pointer: {
-            location: "stack",
-            slot: 0
-          },
-          declaration: findSourceRange("let localValue")
         }],
       })
     },
@@ -207,17 +195,6 @@ code {
             slot: 0
           },
           declaration: findSourceRange("[0] storedValue: uint256")
-        }, {
-          identifier: "localValue",
-          type: {
-            kind: "uint",
-            bits: 256
-          },
-          pointer: {
-            location: "stack",
-            slot: 1
-          },
-          declaration: findSourceRange("let localValue")
         }],
       })
     },
@@ -226,7 +203,7 @@ code {
         mnemonic: "ADD"
       },
       context: ({ findSourceRange }) => ({
-        code: findSourceRange("localValue = localValue + 1;"),
+        code: findSourceRange("let localValue = storedValue + 1;"),
         variables: [{
           identifier: "storedValue",
           type: {