fixed small errors (#261)

* Update generating_the_url_advanced.md

* Update memory_usage_tweaks.md (#1)

* Update serving_files_from_s3.md (#2)

docs/generating_the_url_advanced.md

@@ -38,7 +38,7 @@ resize:%resizing_type:%width:%height:%enlarge:%extend
 rs:%resizing_type:%width:%height:%enlarge:%extend
 ```
 
-Meta-option that defines the [resizing type](#resizing-type), [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omited to use their default values.
+Meta-option that defines the [resizing type](#resizing-type), [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omitted to use their default values.
 
 #### Size
 
@@ -47,7 +47,7 @@ size:%width:%height:%enlarge:%extend
 s:%width:%height:%enlarge:%extend
 ```
 
-Meta-option that defines the [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omited to use their default values.
+Meta-option that defines the [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omitted to use their default values.
 
 #### Resizing type
 
@@ -192,7 +192,7 @@ adjust:%brightness:%contrast:%saturation
 a:%brightness:%contrast:%saturation
 ```
 
-Meta-option that defines the [brightness](#brightness), [contrast](#contrast), and [saturation](#saturation). All arguments are optional and can be omited to use their default values.
+Meta-option that defines the [brightness](#brightness), [contrast](#contrast), and [saturation](#saturation). All arguments are optional and can be omitted to use their default values.
 
 #### Brightness <img class="pro-badge" src="assets/pro.svg" alt="pro" />
 
@@ -371,7 +371,7 @@ The source URL can be provided as is, prendended by `/plain/` part:
 /plain/http://example.com/images/curiosity.jpg
 ```
 
-**Note:** If the sorce URL contains query string or `@`, you need to escape it.
+**Note:** If the source URL contains query string or `@`, you need to escape it.
 
 When using plain source URL, you can specify the [extension](#extension) after `@`:
 

docs/memory_usage_tweaks.md

@@ -22,13 +22,13 @@ Buffer pools in imgproxy do self-calibration time by time. imgproxy collects sta
 
 ### MALLOC_ARENA_MAX
 
-`libvips` uses GLib for memory management, and it brings GLib memory fragmentation issues to heavily multi-threaded programs. imgproxy is defenitely one of them. First thing you can try if you noticed constantly growing RSS usage without Go's sys memory growth is set `MALLOC_ARENA_MAX`:
+`libvips` uses GLib for memory management, and it brings GLib memory fragmentation issues to heavily multi-threaded programs. imgproxy is definitely one of them. First thing you can try if you noticed constantly growing RSS usage without Go's sys memory growth is set `MALLOC_ARENA_MAX`:
 
 ```
 MALLOC_ARENA_MAX=2 imgproxy
 ```
 
-This will reduce GLib memory appetites by reducing the number of malloc arenas that it can create. By default GLib creates one are per thread, and this would folow to a memory fragmentation.
+This will reduce GLib memory appetites by reducing the number of malloc arenas that it can create. By default GLib creates one are per thread, and this would follow to a memory fragmentation.
 
 
 ### Using jemalloc

docs/serving_files_from_s3.md

@@ -53,5 +53,5 @@ You can learn about credentials in the [Configuring the AWS SDK for Go](https://
 
 To use Minio as source images provider, do the following:
 
-* Setup Amazon S3 support as usual using evironment variables or shared config file;
+* Setup Amazon S3 support as usual using environment variables or shared config file;
 * Specify endpoint with `IMGPROXY_S3_ENDPOINT`. Use `http://...` endpoint to disable SSL.