Typo correction for readme and website index

Summary: Small edit `logNEI` -> `logEI` for a non-noisy version in the docs.

Differential Revision: D61997651

README.md

@@ -174,7 +174,7 @@ For more details see our [Documentation](https://botorch.org/docs/introduction)
   ```python
   from botorch.acquisition import LogExpectedImprovement
 
-  logNEI = LogExpectedImprovement(model=gp, best_f=Y.max())
+  logEI = LogExpectedImprovement(model=gp, best_f=Y.max())
   ```
 
 3. Optimize the acquisition function
@@ -183,7 +183,7 @@ For more details see our [Documentation](https://botorch.org/docs/introduction)
 
   bounds = torch.stack([torch.zeros(2), torch.ones(2)]).to(torch.double)
   candidate, acq_value = optimize_acqf(
-      logNEI, bounds=bounds, q=1, num_restarts=5, raw_samples=20,
+      logEI, bounds=bounds, q=1, num_restarts=5, raw_samples=20,
   )
   ```
 

website/pages/en/index.js

@@ -135,15 +135,15 @@ fit_gpytorch_mll(mll)
     const constrAcqFuncExample = `${pre}python
 from botorch.acquisition import LogExpectedImprovement
 
-logNEI = LogExpectedImprovement(model=gp, best_f=Y.max())
+logEI = LogExpectedImprovement(model=gp, best_f=Y.max())
     `;
     // Example for optimizing candidates
     const optAcqFuncExample = `${pre}python
 from botorch.optim import optimize_acqf
 
 bounds = torch.stack([torch.zeros(2), torch.ones(2)]).to(torch.double)
 candidate, acq_value = optimize_acqf(
-    logNEI, bounds=bounds, q=1, num_restarts=5, raw_samples=20,
+    logEI, bounds=bounds, q=1, num_restarts=5, raw_samples=20,
 )
 candidate  # tensor([[0.2981, 0.2401]], dtype=torch.float64)
     `;