Add helper script to benchmark all models

Simply run:

$ ./extra/bench-all.sh

extra/bench-all.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Helper script to run the bench tool on all models and print the results in share-able format
+
+printf "Usage: ./bench.sh [n_threads]\n"
+
+if [ -z "$1" ]; then
+    n_threads=4
+else
+    n_threads=$1
+fi
+
+models=( "tiny" "base" "small" "medium" "large" )
+
+printf "\n"
+printf "Running benchmark for all models\n"
+printf "This can take a while!\n"
+printf "\n"
+
+printf "| CPU | OS | Config | Model | Threads | Load [ms] | Encode [ms] |\n"
+printf "| --- | -- | ------ | ----- | ------- | --------- | ----------- |\n"
+
+for model in "${models[@]}"; do
+    # run once to heat-up the cache
+    ./bench -m ./models/ggml-$model.bin -t $n_threads 2>/dev/null 1>/dev/null
+
+    # actual run
+    # store stderr output in a variable in order to parse it later
+    output=$(./bench -m ./models/ggml-$model.bin -t $n_threads 2>&1)
+
+    # parse the output:
+    load_time=$(echo "$output" | grep "load time" | awk '{print $5}')
+    encode_time=$(echo "$output" | grep "encode time" | awk '{print $5}')
+    system_info=$(echo "$output" | grep "system_info")
+    n_threads=$(echo "$output" | grep "system_info" | awk '{print $4}')
+
+    config=""
+
+    if [[ $system_info == *"AVX2 = 1"* ]]; then
+        config="$config AVX2"
+    fi
+
+    if [[ $system_info == *"NEON = 1"* ]]; then
+        config="$config NEON"
+    fi
+
+    if [[ $system_info == *"BLAS = 1"* ]]; then
+        config="$config BLAS"
+    fi
+
+    printf "| <todo> | <todo> | $config | $model | $n_threads | $load_time | $encode_time |\n"
+done
+