add screen-shot in doc

Author: root

README.md

@@ -7,75 +7,7 @@
 ## Demo
 
 Here is a sample output :
-
-```
-$ postgresqltuner.pl --host=dbhost --database=testdb --user=username --password=qwerty
-postgresqltuner.pl version 0.0.3
-Connecting to dbhost:5432 database testdb with user username...
-=====  OS information  =====
-[INFO]    OS: Debian GNU/Linux 8 \n \l
-[INFO]    OS total memory: 15.52 G
-[INFO]    Running on physical machine
-[INFO]    Currently used I/O scheduler(s) : cfq
-=====  General instance informations  =====
------  Version  -----
-[WARN]    You are using version 9.4.8 which is not the latest version
------  Uptime  -----
-[INFO]    Service uptime : 108d 01h 13m 13s
------  Databases  -----
-[INFO]    Database count (except templates): 2
-[INFO]    Database list (except templates): postgres testdb
------  Extensions  -----
-[INFO]    Number of activated extensions : 1
-[INFO]    Activated extensions : plpgsql
------  Users  -----
-[OK]      No user account will expire in less than 7 days
-[OK]      No user with password=username
-[OK]      Password encryption is enabled
------  Connection information  -----
-[INFO]    max_connections: 100
-[INFO]    current used connections: 7 (7.00%)
-[INFO]    3 are reserved for super user (3.00%)
-[INFO]    Average connection age : 5d 01h 15m 45s
------  Memory usage  -----
-[INFO]    work_mem (per connection): 4.00 M
-[INFO]    shared_buffers: 128.00 M
-[INFO]    Max memory usage (shared_buffers + max_connections*work_mem): 528.00 M
-[INFO]    effective_cache_size: 4.00 GB
-[INFO]    Size of all databases : 37.77 GB
-[INFO]    PostgreSQL maximum memory usage: 3.32 of system RAM
-[WARN]    Max possible memory usage for PostgreSQL is less than 60% of system total RAM. On a dedicated host you can increase PostgreSQL buffers to optimize performances.
-[INFO]    max memory+effective_cache_size is 29.10% of total RAM
-[WARN]    Increase shared_buffers and/or effective_cache_size to use more memory
-[WARN]    maintenance_work_mem is less or equal default value. Increase it to reduce maintenance tasks time
------  Logs  -----
-[OK]      log_hostname is off : no reverse DNS lookup latency
-[WARN]    log of long queries is desactivated. It will be more difficult to optimize query performances
-[OK]      log_statement=none
------  Two phase commit  -----
-[OK]      Currently no two phase commit transactions
------  Autovacuum  -----
-[OK]      autovacuum is activated.
------  Checkpoint  -----
-[WARN]    checkpoint_completion_target(0.5) is low
------  Disk access  -----
-[OK]      fsync is on
------  WAL  -----
-[BAD]     The wal_level minimal does not allow PITR backup and recovery
-=====  Database information for database testdb  =====
------  Database size  -----
-[INFO]    Database testdb total size : 34.47 G
-[INFO]    Database testdb tables size : 9.75 G (28.28%)
-[INFO]    Database testdb indexes size : 24.72 G (71.72%)
------  Shared buffer hit rate  -----
-[INFO]    shared_buffer_heap_hit_rate: 93.74
-[INFO]    shared_buffer_toast_hit_rate: 29.60
-[INFO]    shared_buffer_tidx_hit_rate: 98.08
-[INFO]    shared_buffer_idx_hit_rate: 96.71
-[WARN]    Shared buffer idx hit rate is quite good. Increase shared_buffer memory to increase hit rate
------  Indexes  -----
-[OK]      No invalid indexes
-```
+![postgresqltuner.pl](https://github.com/jfcoz/postgresqltuner/blob/master/documentation/postgresqltuner.png)
 
 ## Use it