Docs: Correct docs around CONF_DIR and -Des.path.conf

docs/reference/migration/migrate_2_0/settings.asciidoc

@@ -172,8 +172,21 @@ environment variable, or the `-Des.config`, `-Des.default.config`, or
 `-Delasticsearch.config` parameters.
 
 Instead, the config file must be named `elasticsearch.yml` and must be located
-in the default `config/` directory, or in the directory specified in the
-`CONF_DIR` environment variable.
+in the default `config/` directory, unless a custom config directory is specified.
+
+The location of a custom config directory may be specified as follows:
+
+[source,sh]
+--------------
+./bin/elasticsearch --path.conf=/path/to/conf/dir
+./bin/plugin -Des.path.conf=/path/to/conf/dir install analysis-icu
+--------------
+
+When using the RPM or debian packages, the plugin script and the
+init/service scripts will consult the `CONF_DIR` environment variable
+to check for a custom config location.  The value of the `CONF_DIR`
+variable can be set in the environment config file which is located either in
+`/etc/default/elasticsearch` or `/etc/sysconfig/elasticsearch`.
 
 ==== `ES_CLASSPATH removed`
 

docs/reference/setup/dir-layout.asciidoc

@@ -57,7 +57,7 @@ Below are the default paths that elasticsearch will use, if not explicitly chang
 
 | conf | Configuration files `elasticsearch.yml` and `logging.yml`. | /etc/elasticsearch | /etc/elasticsearch
 
-| conf | Environment variables including heap size, file descriptors. | /etc/default/elasticseach | /etc/sysconfig/elasticsearch
+| conf | Environment variables including heap size, file descriptors. | /etc/default/elasticsearch | /etc/sysconfig/elasticsearch
 
 | data | The location of the data files of each index / shard allocated
 on the node. | /var/lib/elasticsearch/data | /var/lib/elasticsearch
@@ -83,8 +83,6 @@ on the node. | /var/lib/elasticsearch/data | /var/lib/elasticsearch
 
 | conf | Configuration files `elasticsearch.yml` and `logging.yml` | {extract.path}/config
 
-| conf | Environment variables including heap size, file descriptors | {extract.path}/config
-
 | data | The location of the data files of each index / shard allocated
 on the node | {extract.path}/data