Improve description of configs and parameters in tesseract(1)

Try to make the relationship between configs, -c and --print-parameters
clearer by always using parameter and not variable.

Include the filenames created by each config.

doc/tesseract.1.asc

@@ -36,7 +36,7 @@ IN/OUT ARGUMENTS
 	The basename of the output file (to which the appropriate extension
 	will be appended).  By default the output will be a text file
 	with `.txt` added to the basename unless there are one or more
-	'configfile' options which explicitly specify the desired output.
+	parameters set which explicitly specify the desired output.
 
 'stdout'::
 	Instruction to send output data to standard output.
@@ -54,7 +54,7 @@ OPTIONS
 	Specify the location of user patterns file.
 
 '-c configvar=value'::
-	Set value for control parameter. Multiple -c arguments are allowed.
+	Set value for parameter 'configvar'. Multiple -c arguments are allowed.
 
 '-l lang'::
 	The language to use. If none is specified, English is assumed.
@@ -86,20 +86,21 @@ OPTIONS
 	3 = Default, based on what is available.
 
 'configfile'::
-	The name of a config to use. A config is a plaintext file which
-	contains a list of variables and their values, one per line, with a
-	space separating variable from value.  Interesting config files
-	include: +
-  * `alto` - Output in ALTO format (file extension `.xml`).
-  * `hocr` - Output in hOCR format (file extension `.hocr`).
-  * `pdf` - Output PDF (file extension `.pdf`).
-  * `tsv` - Output TSV (file extension `.tsv`).
-  * `txt` - Output plain text (file extension `.txt`).
-  * `get.images` - Write images.
-  * `logfile` - Write debug file `tesseract.log`.
-  * `lstm.train` - Used for LSTM training.
-  * `makebox` - Output box file.
-  * `quiet` - Write debug file to /dev/null.
+	The name of a config to use. A config is a plain text file which
+	contains a list of parameters and their values, one per line,
+	with a space separating parameter from value. +
+	Interesting config files include:
+
+	* `alto` - Output in ALTO format ('outputbase'`.xml`).
+	* `hocr` - Output in hOCR format ('outputbase'`.hocr`).
+	* `pdf` - Output PDF ('outputbase'`.pdf`).
+	* `tsv` - Output TSV ('outputbase'`.tsv`).
+	* `txt` - Output plain text ('outputbase'`.txt`).
+	* `get.images` - Write processed input images to file (`tessinput.tif`).
+	* `logfile` - Redirect debug messages to file (`tesseract.log`).
+	* `lstm.train` - Output files used by LSTM training ('outputbase'`.lstmf`).
+	* `makebox` - Write box file ('outputbase'`.box`).
+	* `quiet` - Redirect debug messages to /dev/null.
 
 It is possible to select several config files, for example
 `tesseract image.png demo hocr pdf txt` will create three output files
@@ -334,14 +335,14 @@ Tesseract 4 LSTM OCR engine.
 CONFIG FILES AND AUGMENTING WITH USER DATA
 ------------------------------------------
 
-Tesseract config files consist of lines with variable-value pairs (space
-separated).  The variables are documented as flags in the source code like
+Tesseract config files consist of lines with parameter-value pairs (space
+separated).  The parameters are documented as flags in the source code like
 the following one in tesseractclass.h:
 
 STRING_VAR_H(tessedit_char_blacklist, "",
              "Blacklist of chars not to recognize");
 
-These variables may enable or disable various features of the engine, and
+These parameters may enable or disable various features of the engine, and
 may cause it to load (or not load) various data.  For instance, let's suppose
 you want to OCR in English, but suppress the normal dictionary and load an
 alternative word list and an alternative list of patterns -- these two files
@@ -371,8 +372,8 @@ load_freq_dawg       F
 user_words_suffix    user-words
 user_patterns_suffix user-patterns
 
-Now, if you pass the word 'bazaar' as a trailing command line parameter
-to Tesseract, Tesseract will not bother loading the system dictionary nor
+Now, if you pass the word 'bazaar' as a 'configfile' to Tesseract,
+Tesseract will not bother loading the system dictionary nor
 the dictionary of frequent words and will load and use the eng.user-words
 and eng.user-patterns files you provided.  The former is a simple word list,
 one per line.  The format of the latter is documented in dict/trie.h